I think it is hard to convince local store, because to do it, he needs a lot of customers that are using bitcoins.
In most countries, bitcoin isn't that popular. So it is just simply not worth it for them.

though it not easy for both options...but I think if bitcoin is able to circulate or widely recognize as whole source of payment...I think only then it will be easy....

the best success for local stores is easy
set up a prepaid bar tab.
EG hand the business upfront enough fiat to cover them for a couple weeks(think bar tab) and tell them if ask to pay by bitcoin, just check the app (your website) to inform the customer how much bitcoin the total is. display the QR code (your bitcoin address) and when it says payment received let the customer leave with the 'cash' receipt, and take the fiat funds out of the "bar tab".
and you just refill the bar tab if it gets low.
no risk to the retailer as they already have the cash
later on they can set up professional services(bitpay/coinbase) and/or go solo after your introductory period.

no risk to retailer, no weird accounting process needed. not even needing to change anything on the cashier register, the cashier just rings it up as a cash transaction because the cash is already in the retailers safe.

but as i said trying to get an employer to mess around with business accounts, obtaining bitcoin and dealing with taxes.. well thats alot of work

It's hard for me to choose 1, but I think need to be convince first the local store , if they already convince about bitcoin adoption and use it as a payment, accepting employee to pay via bitcoin will follow if they know that there are more use bitcoin in there country of course they want it to accept.

Both of them is difficult to convince, local store difficulty are: they need to convert their goods price from fiat into bitcoin and they need to change it everyday because the bitcoin price is changing everyday, and the other obstacle is the transaction speed confirmation
We always do financial management when we have source of income in this case is salary, we cant do financial management if the money we received each month is different

to be honest i do not like this bar tab idea much. here is why.
you play the man in the middle. you are handling other peoples money.
this means you run a business and need to pay taxes, most likely some kind of licence and also receipts.
then there is also the risk, that the owner will just keep your money, because what do you want to do about it.
i do not see an incentive to go solo. the owner could just stop using bitcoin if you stop the risk free middleman service.
if you want people using bitcoin, then let them use it, do not do it for them.

Both are difficult in this moment. Giving salaries and receiving money for goods you sell are regulated with laws. Its not something that employers or store owners can just decide to do in real life, and in every country. Maybe there is ways to manipulate with this laws, and maybe even to find some hole in the law, but that again depends from governments and state laws.
Its not going to be easy for many countries, there is free states, and places where people can be free to do many things, but also there is other side. I don't think this will be possible in every country.

Interesting question.Both employers and local store merchants will accept bitcoin only if the bitcoin

price becomes more stable.What if you get paid a salary in btc and the next day bitcoin price does 25-30%

down?And what if you were a merchant and your revenues are in btc and the price does down?

both aren't easy but the local store will be lesser hard,they'll catching wider area of payment option to increase their selling especially if they also opening a store in internet,the fluctuation is not going to be a problem because there's exist service like bitpay which will exchange the paid bitcoin to fiat directly at the same time

I think it is more easier to convice your boss to pay you in bitcoin , if he uses bitcoin to but if not he will be not able to pay you he pay you with digital currency which is using to pay some employes. And for local store some stores now are accepting bitcoin as a payment where they gonna do is to scan your bitcoin wallet and send your payments.