Infiniti: Power Window problems

I have a 1994 Infinity Q45 and my front passenger side has a problem
with the power windows. The Windows can roll down. But to roll up, I
have to push the windows up with my hands while pressing on the window
switch. Essentially, the windows needs the force of my hands to roll
up.

What can be the problem? Do I have to change the Window motor,
regulator, or both? Also, is there a Q45 service manual that can show
me how to install this stuff myself?
Thanks,