Other Permobil wheelchairs will have identical instructions - but keep in mind each wheelchair user's needs are unique and they use their chairs differently.
Ideally, it is easiest to mount when a wheelchair is not occupied.
Optional:

It is easiest to mount to a wheelchair when the chair is unoccupied
Determine the mounting side for best access. (consider avoiding the wheelchair controls)
In this example - we have mounted to the left side of the chair.
For clarity, the arm-rest is folded up.
For this type of chair, we are going to mount to the Uni-trac.
Before we begin mounting, try to see if there is anything obstructing the mount and post.
Using a tool (we use the 3/16" Hex Key in this picture ), remove the cover that is on the end of the Uni-Trac rail.
If installed correctly, it should "pop" out easily. If not, you may need to use a flat-head screwdriver to pry it out.
Once the cap is removed, set it safely aside.
You will need this cap for re-assembly.

To mount to the Uni-Trac, we will use the Wheelchair Adapter Plate 2 (WC-AP2).
Remove the WC-AP2 and the hardware bag that has:
Align the square nuts with the two channels in the Uni-Trac.
Insert them one at a time, and slide the WC-AP2 to the desired location.
You may have to tighten or loosen the screws to make this process easier.
Alternatively, you can insert the nuts first - and screw the plate down after.
Slide the WC-AP2 into the desired position along the Uni-Trac, then
Using the 3/16" (or 5mm) Hex Key, tighten all four screws by turning them clockwise.
Using the cover (that we removed in step 1) - push it back in to the Uni-Trac
If the user typically is seated at a tilted angle, it would be more appropriate to use an Adjustable Wheelchair Bracket (WB).
In this example, we attach a Solid Wheelchair Bracket (WB2)
Screw the WB2 down using the 3/16" Hex Key and the two short bolts that are packed with the WB2
There are multiple positions to mount the WB - choose the position that works the best.