If the bottom bracket bearings need to be serviced, and they likely do, then it's worth it in my opinion to pull the crank arm(s) off to clean/inspect/regrease the bearings. Yeah, it can be a bit of a pain, but it's a job worth doing to make sure it keeps working for many more years.

The job's significantly easier with a cotter press, but you can improvise. I've used the vise and socket method on a really stubborn old Peugeot.