Following forum advice i simply drilled through the rubber insert that the bar end weight screws into.I drilled around the outside like the figures on a clock face.
I screwed a bolt into the fitting and pulled it out.
I confess to going a little anal...i used a wood bit close to the internal circumference size of the bar and reamed the remaining rubber out.

The bolt that came with the acerbis guards is too short to carry the weight and then catch the guard fitting/ 'rawplug'..going to collect a few when shops are open.

TBH Im not sure how the weights and guards setup will look/as so far the levers may need a tweek but will report back when its sorted.

I have filled the bars with silicone too.