Now this is a quick and dirty method and sure there are more professional ways to do this but it works great for me, all in it took less than 5mins.
1. Take bottom pin out and using a fine cutting disc on a dremel cut a groove along threads and a bit out the screw head.
2. Take grub screw out the top of the centre post, drill down with 1.5mm drill bit, don't work it to long, you don't want to melt that insulator.
3. Assemble and job done, works a treat grin emoticon
No need to cut another slot in the centre post for the juice to come out as with wire in there it leave a big enough slot for juice to come through.
Downside is that you have exposed the copper.