I never bought a bearing removal tool but changed quite a few engine bearings. The oven really helps and is required for some difficult engines. Maybe you can find a used toaster oven at a yard sale or flea market, they work well for this. I found a set of brass punches that came in different sizes that I usually used although sometimes a regular punch of a different size was needed. Front bearings are usually pretty easy but rear bearing can sometimes be a challange. I had one engine that when I tried to knock out the rear bearing, the inner race and balls fell out but the outer race stayed in. Because of the case design, there was no way to get a punch on the outer race. So, what I had to do was carefully use a dremel and small chisel to cut the race and then it finally came out. It was a nightmare and I damaged the case a little but it didn't affect the engine. It ran fine afterward. Oh, and sometimes I had to use a bolt, nut, and washers through the two bearing to get them to seat fully. If you put them in and the crank doesn't spin freely, one of them isn't in all the way and you might have to do that. Hope that helps.