weird turn signal lenses

[the Ferret]

Ok so went out to replace the t/s lens. (btw my service manual was no help..it's for a 13 lol)

Removed black tape,
Removed yellow part of lens which had crumbled all around the edge,
Found a single phillips head self tapping screw on bottom of t/s and removed it.
Tried pulling out old lens but it wouldn't budge.
Looked closely at new one and found these little tabs...hmm
Turned lens counter clockwise 1/4 turn and out it popped.
How complicated does this have to be?
Reversed procedure and replaced screw and we are done.
Weird.

here's the old lens