I'm finishing off a bathroom renovation - tub surround, new faucet, shower head etc. I wanted to replace the tub drain as well since the plug doesn't work and the cross piece is missing. I managed to get the old one off even though the "cross" was gone using a special tool. Now when I go to put in the new drain I realize the rubber washer that comes with it is supposed to go between the tub and the drain underneath. I can't get at the underside of the tub so how do you get the old washer out? I'm afraid to touch it in case it dislodges everything and I can't get at it. It wasn't leaking before - I just wanted to replace it to match with the new shower fixtures.

If you haven't moved the rubber washer then just leave it in place and install the new strainer, as long as your sure there was no leak on the drain before.