Changing batteries in a revelation laser collimator

[Dom1961]

How do I change batteries in the revelation laser collimator?

[David Smith]

If it's the same as mine then you have to unscrew the back end of the tube (not the end you put into the eyepiece holder). Careful as there is a little spring inside which will pop out! Inside is what I assume is the laser housing (silver / gold coloured housing) with a little loop / dome on the end. If you unscrew this then the batteries are located in here.

[Dom1961]

Mine has a dome with a hole in, but how do you unscrew it?