Very simple to do
You'll need one of these switches or a similar style switch:
https://www.ebay.co.uk/itm/12V-Momen...72.m2749.l2649
On the switch I used there are 4 pins. 2 are for what you want to use the switch for and 2 are for the LED.
There are 2 wires at the factory boot release switch at the front of the car (the one below the bonnet release lever), you'll need to splice into these two wires and run the pair of wires to the boot lid and connect to the relevant two pins on the switch. That'll get the switch working to open the bootlid.
Then to wire up the LED i simply ran a pair of wires from the boot courtesy light positive and negative wires to the switch.
Very simple and only takes about an hour to do with most of the time spend running wires.