...I had an autoleads adaptor for my 1999 Clio...
To fit it you had to:
pull the seals away from the doors by the a frames
remove the a frames
remove the 2 screws in the dash by the doors, remove the 3 screws in the top of the dash by the window, remove the 2 screws holding on the cover around the steering column, then remove the final 2 screws holding the dash on.
Pull the top of the dash forward and lift out of the car
Unplug the correct cable going into the remote display, plug the autoleads adaptor into that cable, and the 3.5 mm plug into the stereo...
...if your instructions are anything like that then you are in for a real treat! It takes a bit of time and effort to do this - but it isnt really that tricky, you just have to have cofidenence on what you are doing...
..btw, Id disconnect the battery as well, wouldnt want an airbag going off would we?!
From what I can gather, the connects2 boxes are better (They keep the remote display as well), in that they just connect to the adaptor which would have plugged into the stock stereo....no messing with dashboard to fit....
...good luck!
Adrian