My experience replacing a Low Profile Lewmar hatch lens originally installed in 2006. The new lenses and guidance were provided by Tony D'Andrea at hatchmasters.com.
The wind blew the hatch over during one of our overnight trips. The lens cracked when it hit the deck. Looks like a stress fracture where the friction lever attaches to the lens.
Remove the hinge cover.
This takes a little effort. If very old, they may break off, so be sure to have your new parts before you do this.
Old-style spacer needs to be removed.
With the split on the opposite side, pull off the spacer.
Spacer after removal.
Tap the hinges to the center, so you can remove the hatch lid.
If old, this may take some heavy tapping with a screw driver and hammer. These should get discarded, so no harm done.
Once both sides are centered, you can remove the hatch lid and lens.
Old spacers removed from the hinge.
Unscrew the attachment of the friction arm from the lens.
The hatch frame pulls apart at this split. More later.
The friction arm parts that get removed from the lens.
The handles - removed and dismantled.
Cleam em up and re-use them.
The empty handle hole.
Both handles. Just need to clean and lub.
Hatchmasters includes a new pair of gaskets for the handles.
Prepare to pull the frame apart and remove the lens.
Remove 2 screws on one side of the frame.
If you remove all 4 screws, you run the risk of pushing the slide bar into the frame when you push them back together.
Revealing the slide bar as you pull apart the frame
I don't know what this is really called, but I call it the slide bar. Be sure to leave the 2 screws on the left in place so the bar does not slide when you reassamble.
Pull evenly to separate the frames.
Both sides of the frame slide right off of the old lens.
In reverse, slide the frames back onto the new lens.
I cleaned the frames before reloading. Note that the gasket comes attached to the lens. I also leave the paper on the lens until I am ready to install.
Prepare to reinstall the cleaned handles.
Note that the handles only fit 2 ways. Only one is correct. If you imagine locking the hatch, you will figure it out.
First handle has been reinstalled.
Insert the new hinges.
Line up the refurbished hatch and insert the hinge components.
Insert on both sides
Press them both to the center so you can slide the frame onto the hinge
Slide hinge components outward and insert the compression fitting
Pushing the hinges out into the frame is somewhat frustrating because it is a tight fit, but be persistent. It does work.
Finally done.
This is the new compression fitting the pushes the 2 outer hinge components into the frame. I used two small Allen wrenches to spin the sections in opposite directions.