If you know your seed and haven't imported any private keys that Electrum didn't generate, you don't need your password. Electrum wallets are deterministic, the password just protects the seed and imported private keys. Back up your electrum.dat (just in case) and delete it, then start Electrum and it'll give you the option to restore from seed. Enter the seed and let it do its business (it'll generate addresses and download transactions, maintaining whatever gap limit you set).. once it's done, pick a password you'll remember.