there's normally a key pool of a thousand new generated addresses beyond the ones currently in use
Correct. Go to Help > Debug window > Console and enter
getwalletinfo to see the details:
but if i wanted to..... (geek here), is there a step by step guide or something?
I always thought you'd need to create a new wallet, but
Stack Exchange says you can use
-upgradewallet.
If it were me, I'd go old school anyway: create a new wallet, make a backup, make a few more backups, and transfer funds from the old wallet to the new one.