need info on spindle rebuild and deck ???

Greetings new member here, and new to me G1800 owner...
I haven't found this info in my search. I am rebuilding a spindle hub on the 54" deck of my G1800.

I will be using a new hub as the old bearing seized and spun in the hub.

Question: Do I press both the new bearings on to the shaft first, or do I press one of the bearings into the hub first and then press the shaft in then the other bearing?

Also the bolt in the tension arm is frozen solid in the bushing, in my attempts to free it what has now happen is that the entire arm assbm. with the bolt is moving freely in the deck. In other words the arm is not rotating on the bushing but the bolt spinning in the deck. Will there be a potential problem leaving it like this as I am not sure how and if I will be able to get the arm off without cutting the bolt off from below the deck,,then who knows what will have to be fixed.

This tension arm was apparently not working for some time, at least in its present state the arm can apply tension...just my thoughts...any advise is greatly appreciated

thanks