It has been so long since I replaced one of these I can't remember (sorry). Pretty sure I used average hand tools though. If you need to use a hammer, find a socket or something the right diameter and use that. When pressing/hammering bearings it's important to keep the force on the race that's being pressed. In this case I believe it's the outside race, so put pressure on that. FYI, It should be the same diameter as the bearing that you took out, so it should require similar force. If the old one fell out, then the new should "fall in". If not then you should double check dimensions of new bearing and compare to old. If it's not the same, then you got the wrong bearing. If you don't have a way to measure you can get
cheap plastic dial calipers that are actually pretty darn accurate. I have a pair in my tool box (SPI brand) I've been using for ~30 years. They came as a "free gift" with a larger order I made from SPI back in the 80's. Initially I thought they were a joke, but I use them in "semi harsh" environments and they've held up remarkably well. I still trust them down to ~.01"
. Tim