Re: how difficult would it be to change out my gimbal bearing on an alpha one ? 1989
You use the alignment tool to get the bearing itself aligned in the carrier (use it's installed). That makes putting the drive back on a lot easier.
I would strongly recommend you get an alignment tool if you're serious about doing your own maintenance. Checking the engine alignment is an annual maintenance item. You can pick them up on fleabay really cheap, no excuse not to have one.
Chris.....