radamm offers you good advice. Looking at that single, heavy white cable coming out of your distributor, yea, it does look electronic.
However, to answer your question: you can't remove the advance mechanism without disassembling the distributor. And, you need to remove the distributor from the front cover to do that.
Yea, this is a hokey design - why Marelli put the advance weights to the top, instead of copying the configuration of the earlier Bosch distributors, is beyond me.
San Juan Capistrano, CA
'63 Guilia spider
'65 Guilia Sprint GT