Tail light fumble

[Nick C]

Hi Harley Friends,
Can anyone give me guidence on reattaching my rear brake/turn signal?
The allenbolt doesn't seem long enough to thread into the light housing. The bolt can not be removed while the Tombstone taillight is in place. The left light has the same bolt.
Pictures let you see what I am up against.

The easiest stuff throws you for a loop
Thank you!!

 

[Breeze3at]

That bolt should thread into the signal housing from the inside (close to tombstone) part of the assembly. The allen head is barely visible in 1 photo.