jd 450 front cross bar

Hello all < i am new to this forum > I have a jd 450 straight and i am slowly repairing all that is wrong with it. It staerts and runs great, did a new injector pump, all hoses, seats etc, starter, alternator and all wireng harnesses.
Now my biggest job yet front cross bar. The bushing holes are gone and it was welded several times which is now broke.
I have a new cross bar. Quetion is can i change it without removing the track bars ?
Once i have the cross bar unbolted can i not jack up...

jd 450 front cross bar

jd 450 front cross bar