Greg you got this. It’s not a complicated process, especially for this engine. You don’t have to worry about steamer wheel quartering. I buy my wheels from Hennings. I did this same replacement a few months ago on several No 8’s.
From the big box stores buy a faucet handle puller and a woodworker vise. (See pic#1) On the puller I had to grind down one leg to better fit between the motor frame and the wheel for O gauge engines. (See pic#2). As purchased will work fine with standard gauge. Just pull one wheel, remove axel from frame, pull other wheel from axel, punch the gear off of the wheel.
Use the Wood vice to press the gear on new wheel. Then set geared wheel into vice with axel perpendicular to it and press it on. Slide assembly through motor frame and use vice to press other wheel on. Check for spacing between wheel, frame and ensure gear mesh are all smooth. Than repeat and your done.
I have used this on 8s, 10s, 249 and 253 also. Just take your time and you will be fine
.
