DirectElection.org is designed to help you send your own signed postal letters to the members of the Electoral College from states won by Donald Trump to ask them, respectfully, not to vote for Trump.
The electors have already received a ton of e-mail and news attention, but a personal letter means a lot more. A single good old-fashioned, voter-to-voter personal letter is probably worth a thousand e-mails.
The sites has prepared a ready-to-print, customizable mail-merge in Microsoft Word and a set of ready-to-print Avery Standard 5160 labels for envelopes. Just download, add your name and address (customize more if you want), print, sign, put them in envelopes, address the envelopes, apply stamps, and mail.