I lost my key under the fron passenger seat cavity. Any pointers on how to remove seat - easy/diff? or shall I try to remove the door sill and check if I can access the under seat from the passenger door side.

FYI - there is a big/deep cavity under passenger seat and things can easy slide into it

 

It is just like removing any power seat. You'll have to undo all the bolts on the seat rails and disconnect all the electrical connectors. Also worth mentioning the the bottom seatbelt anchor is integrated into the seat on the L462.

 

Thanks! I don't think I would need to remove the connectors as by moving the seat all the way forward I can reach the ky but not good enough to grab it... I think by unbolting the rails and lifting it about an inch (with connectors on) should be possible.

If I have to remove connectors I think better to disengage battery as there are airbags in seats...

 

If you can reach the key but not grasp it I would first try something sticky on a stick or stiff flexible wire.
Like sticky tape with sticky side out. Or chewing gum. Or maybe a tube on a vaccuum.