Double Hungs in a Double Wide!!!

[Ron J. Moore]

I want to replace the windows in a double wide mobile home....the outside window has a flange that is screwed in and visible; then there is a "inside storm window." I have noticed this winter a build-up on condensation so I figured to go to Lowe's and order Pella windows.
I have done regular house windows in the past, this is the first mobile for me. My questions that hopefully you all can answer for me are:
(1) Can I just remove the two windows, order replacement windows just like a house and install? There is no edging in the framing, so I guess I would just level and plumb?
(2) If I have to go with the flange type replacement, would I put the silicone caulking around the flange before setting it in the opening -- and then run a bead around the inside? Would you be using the screws on each side like a regular window? Like I said, I have never done these
type windows and am a little apprehensive. The time I installed them in my home, the savings was significant and it was straight forward and fast.
Thanks for any help, Ron