There's two basic paths to doing this on your terms:

0) figure out policies re: PTO at termination, vesting, etc, so you don't get screwed

a) find new job

b) plan how to distribute knowledge to others in 2-4 weeks (or whatever separation time is customary)

c) bring plan to current management

d) work on the plan if management accepts, or chillax if management deems resignation immediate (or check with new employer about moving start date)

Or

0) same as above

a) plan to retire

b) make it known you are planning to retire and push back on new work

c) finish up things / document and hand them off

d) when you run out of things, give 2-4 weeks notice

e) tie up loose ends you forgot (or don't if your resignation becomes immediate)

f) chillax (and fix a lot of stuff at home you didn't have time to realize was broken)