Manual or electric? Either would need the front inside a post trims pulling out (watch alarm sensors 7 wires), then sunvisors and grab handles (undo the screws nearly all the way but not fully so the captive screws stay in place), then press the screws in as far as they go while pulling out the handle/visor fixing. Putting them back in sometimes requires trimming so they fit back in the metal roof panel. Remove the sunroof glass - manual type just open the glass fully, then press the small red button to release the handle, then lift up the glass about 45 degrees and the 2 front hinge plates will slide out of the slots. Easier with 2 people
Electric roof move back to half way, then undo the 2 torx 20 screws in sides of rails holding glass in place (should see them easily at half way point). Slide out glass again with an assistant.
Now, it's possible to hang down the front of the headlining and get to the 10mm bolts holding the roof frame in position. Undo all of these, and also the electric wiring if electric sunroof type. The underframe then should come out downwards and rest on headlining, the sunroof main frame can be lifted out. You may want to unclip the B post trims (safety belt top mounts unbolted too) to prevent headlining creasing too much, although as long as you're careful this crease will go once back together
The sunroof frame seal is a foam rubber type and to some extent a memory foam. Replacement is normal when taking the roof out to stop the well known creaking problems, but make sure all the old seal & glue is removed, and the plastic is thoroughly degreased otherwise the new seal won't stick properly. Also when fitting the seal, don't stretch it, and when fully stuck round, make a diagonal cut at the joint to reduce chance of capillary water leak. Refitting is the hardest as you need to centralise the roof - renault do a cheap fitting kit so get one of these - 2 white nylon dowels and a red glass tensioning block. The rest is reverse of removal, but various mods exist to stop noise so see your dealer for the kits as these sunroofs can be really bad if not modded correctly.
Lastly, make sure it's the sunroof leaking as I worked on a 3 door clio 2 with a roof leak which I traced to a pinhole in the roof joint panel seam sealer (original factory fault) above the b post - caused a leak into the headlining above the steering wheel/driver's head!