The issue really isn't the pressures, it's taking it apart and losing timing of the valves in the pump.
That's the reason you see tamper proof screws in the top of the pump.
The leak is easy to fix, but you need to keep the parts in the proper order and proper orientation.
I have see many a pump damaged or disabled by DYI repairs.
This is the O-rings that are leaking.
There are kits to do it, I can point them out, but I almost always recommend having it professionally rebuild.
Resealing / rebuilding it requires all these parts to be removed, and reinstalled perfectly.
The barrels above rotate in housing and that sets the timing curve of each pump.
If you replace hard parts like the pump and springs you will not be able to know where the valves should be positioned and what shims are needed to get the right travel distance of the pumps.
