'97 Concorde Sunroof

ok..here's the deal. The sunroof is very balky in all operations. It'll vent....sometimes I need to help by pushing it up. Closing the vent is again very sluggish. Going to a full open position, it goes, but slowly. I need to push it with my hand to close it. The motor runs, but of course stops when the roof stops. I tried basic lubrication to no avail.

My thinking is that its a worn out motor because it falters in all operations. I tend to think if it were a linkage problem that it might be sluggish in one mode.

Is my thinking sound ok? If I were to pick up a used motor, how hard are they to change? Where's the dang thing located? Any other tips? Thank you so much in advance for any responses.