To remove the boot lining, grab the rear of the plastic section that the parcel shelf normally sits on and give it a good sharp sideways tug. This should detach it from its mounting (it's only a pop-in fixing, so nothing will be broken.) You should be able to unhook the lining from behind it and peel it from behind the boot seal rubber. Once you have completed the job and re-fitted the lining, hold the plastic section in place and give it a thump to lock it back into its mounting. That's based on the hatch. I imagine the tourer would be similar.
I've got the laguna 2002 model sedan
I've tried this and it did work. I got the lid open and it was easy to refit the lining. Thanks heaps Horatio Cheers.