jack car up, clean up area and inspect for where the leak is 100% coming from. if nothing obvious run up the road and back then check again. if still nothing, get the box oil warm on a longer drive again
if your 100% satisfied its that area for the leak then the seal may be unseated or simply loose bolts. worse case the boot itself on the shaft (this is the seal) may need replacing
basic job to check is firstly try nipping the 3 retaining bolts up (dont overcook them, they are into an alloy box and can strip)
if not loose then, drain box oil from drain hole on the bottom (looks like a sump plug near the selctor on bottom of box) loosen hub nut, jack car up, remove wheel and top hub bolts to strut, undo 3 retaining bolts to the box that hold the boot/shaft/seal. remove shaft with boot/seal from box end if you have the clearance or completely if your struggling (can be a wiggle) inspect boot and clean/reseat and fit if all looks well.
refit is reversal of whats above and test again
