Hi Vinny,
I think the guys here can help keep your head above water.
The first thing is to get the gear lever out of the way.
Then you can deal with the advance unit:
You can see the unit is already threaded to screw in a removal tool, I think most people do not bother with the special tool.
If you do not have the tool, find a bolt that screws into the thread (5/16” unf), the longer the bolt the better.
You already have the fixing bolt removed, your new bolt is a bigger diameter.
Screw the bolt into the unit (not tight), hold the end of the bolt with mole grips or pliers and pull back hard. While the bolt is under tension give the tool that you are holding the bolt with a few sharp taps, (a spanner is ideal for tapping the bolt/tool with).
The blows should be outward rather than sideways, and should be sharp rather than hard.
This is located on a taper fit, so the tension combined with the shock should see the advance unit ‘pop’ off.
An alternative shown in this video will work if it proves stubborn.
https://www.triumphrat.net/vintage-...how-do-you-remove-the-auto-adavance-unit.html
The cover will either be easy to remove, or glued on with gasket sealant.
Tap around the edge with a rubber or plastic hammer to crack the gasket seal.
Do not be tempteed to:
A) use a lever in the gap between the two faces, is is very easy to ruin them both.
B) Hit the boss that tolds the pressure switch hard, it is easy to break.
Good Luck
Regards
Peg.