That's a tricky one.  You have to pull back the carpet under the driver's
feet from the top left.  Under there you'll find a black metal cover.
Remove the screws holding the cover and the cover.  Under that cover is the
relay.

In principle, you can also get it out by simply pulling it out from the top
by tugging the right bundle of wires, thus avoiding pulling back the carpet
and removing the metal plate.  It's a little tough to stuff back in later
and you've got to trace the right bundle of wires to it.

I dissected the relay after it failed and, not surprisingly (given the
location), it was full of water.