6/'87 325is 180k+ miles

I read some of the archives, but didn't come across really my situation...

After sitting for almost 3 months, my car will not start. When I turned the key initially it sounded like it was trying to start/ turnover, successive attempts a few minutes apart progressively sounded less likely it would start until it got to the point I just heard 'cliking sounds' when I turned the key. My dash lights worked the whole time and I was able to turn on the headlights and highbeams just fine. I forgot to check the fuses.

I have had similar issues starting the car in the past, especially when it sat for awhile, not this long though, and could get it started after a few good tries.

I think it is the starter motor or related piece, would this sound correct? I don't have my Bently maunual with me, it is in the car which is in storage a ways away from me now. How difficult and time consuming to change out the starter? Any good links for instructions test for this and/or change out this or related parts?

Thanks a lot in advance!