It's a slip fit, not press fit. So you need to get the bottom of the bearing block hot, use a small hammer and a flat head to gently tap the bearing out from the other side (you simply slide the spacer out of the way with the tip of the flathead. Be careful not to lose the spacer whe . You do this. Then, heat the other side up and tap it out with a 3/8" or 1/2" extension.
Clean the hell out of it and be sure the landings are perfectly clean and clear of debris.
Then heat it all back up and install the new bearings and spacer.
I like to install the bell and snug the pinion nut up while it's all still hot time be sure they seat perfectly. Then pull the bell back out and lock tight everything and reinstall.
If that bearing was that bad, I bet that heli was all over the place vibrating huh?