You can do it several ways.
How to adjust door glass 1970 mustang.
The best way to solve the problem is to do exactly what ford did for 1970.
It is easier to install then the factory 69 bond in.
Mine are all new 70 glas.
Just those 3 bolts and 1 nut do all the adjustments you need.
Keep in mind that a little adjustment at each point makes a huge difference so adjust in small increments.
This bolt is in an oblong hole in the door.
For you guys that are familiar with the door window adjustment.
Jack it up a little at a time it is easier to lift a little more than it is to lower it to the right heigth if you go too far.
The regulator where it mounts to the window bracket on the left side in the pic has a slot that allows the window to be adjusted forward or rearward.
Usually the door will be low and not high in the rear.
I found this pic on line that may help explain my problem.
This is because someone rebonded the glass into the brackets and scraped out the old bonding.
It turns slightly hard one way which i think is where the spring tension is and easy the other way.
Did you ever think of going with the 1970 mustang bolt in setup.
My drivers side window has been really hard to turn up and down.
This what we mean by loose glass in the doors of a 69 mustang.
Are you trying to adjust the window fitment.
The old bonding is the alignment.
Hey guys have a 69 mustang with the 70 bolt in glass.
Replace the glue in glass with 70 type bolt in glass.
My window wont slide easy i.
First try to lift up using your hands.
If this does not move it enough use a floor jack but put a 2x4 between the jack and your door edge to spread the load.
Took out the regulater and it seems to work good.