Update, my sill is fitted, and apart from a car fire all went well.

A little guide of the steps.

Firstly, I got my sill, and cut the parts thhat I didn't need off. these were the ones that got in the way. The top curve thing and the front of the sill that curves in.

Marked out and cut with a regular cutting disc.

Done

Now I offered it up, adjusting it to fit with the original swage line, then I marked out where to cut, and prepped the area I was welding to.




Now I needed to what Dingla advised. I cut through both skins. But before that I drilled holes for plug welding.
Also just a reminder for you, WEAR SAFETY GEAR,


Then I did the deed and welded it on, Final checking everything. This when I had my fire. My dad was outside luckily, and as I was welding, a little bit of waxoil that was on the bit I was welding caught fire, and that shit spreads quick, then within about 5 seconds, waxoyl was onfire in half the sill, and we were running for the hose pipe, as the air line didn't do a thing apart from feed it. Lesson learnt. If you put Waxoyl in your sill, have a fire extinguisher, hose and an airline there just in case and have someone on fire duty, ready to put any little flame out!!!!

Any how here's the finished result



Not a bad fit if I say so myself.

*Disclaimer*

This is a guide of what I did. I am not responsible for anything you do, and what ever happens when you do what ever you do to your car, is not my resposibility or fault if it goes wrong. As i'm sure in this sue-a-guy country, someone will try and take me to court. And I was 14 when I did this, as it's just been my birthday

Thanks to all that helped, and a big thanks to dingla for the advice, it has worked perfectly.



Cheers all