Hi how does this work then? Is this the right thing to do?
1) Backup wallet.dat from your 0.12.1 folder
2) Delete wallet.dat from your 0.12.1 folder
3) Install 0.13.0 and open it so it generates a new wallet.dat file (this is now the HD wallet file I guess?)
4) Sync the wallet, once it's synced close the client.
5) Now you have a synced 0.13.0 but you need to boot 0.12.1 wallet again to send to the empty new 0.13.0 wallet...
how do I continue from here? I need to have 2 different versions of Bitcoin installed at the same time..
1) open your phone
2) do a transaction of all bitcoins in your phone (bitcoin android wallet)
3) change to bitcoin core and create HD wallet
4) do a transaction from phone to bitcoin core HD wallet
consolidate bitcoins.
use the network.
pay the fees.

Too risky to use phone to move big funds over there, also, to stay anonymous one would need to send several different transactions which means more fees, this is so annoying.
"Backups of HD wallets, regardless of when they have been created, can
therefore be used to re-generate all possible private keys, even the
ones which haven't already been generated during the time of thebackup."
if i understood correctly this mean that the 100 pool address is olved, when you restore a backup after you have used all the privatekey previously generated, and added a new one? i can do this now without worrying about losing my coin?
Yes. Only thing you need to worry about is backing up every time you encrypt the wallet or change the password.
So this means you can use the old wallet and don't need to send coins to the new wallet?