I doubt online petitions work, but just to give this cause a few more eyeballs, here:

Colbert is another I'd like to see shunned, but I doubt any of them care at all. Their boycotters are all bitter, gun-clinging deplorables for whom they have utmost contempt; they are loved by Hollywood celebrities and their sycophantic audiences who applaud their every opinion. The Tunnel Dweller

Jimmy Kimmel Boycott has Over 150,000 Signatures — All Started When Kimmel Mocked FLOTUS  . . . "A petition to boycott the entertainer’s show has been signed by over 150,000 people after he decided to mock First Lady Melania Trump’s accent during one segment of his show.

"Kimmel received serious(?) backlash for mocking FLOTUS’ Slovenian accent, by showing a video of her at the White House Easter Egg Hunt reading a book to children." . . .

. . . "The whole tiff came to an apology from Kimmel, but not for his attack on FLOTUS and only if he cause offense to the gay community.

“ 'By lampooning Sean Hannity’s deference to the President, I most certainly did not intend to belittle or upset members of the gay community and to those who took offense, I apologize,” he said in a statement." Emphasis added, TD

Hat tip for this to Regis Giles at Hollywood Conservatives for Trump

• Kimmel's sponsors and their contact info
• Here Is A List Of 20 Sponsors To BOYCOTT & Hit Jimmy Kimmel Where It Hurts

Kimmel, Hannity dial back feud

. . . Hannity said for him the fracas [was]never about Kimmel, but about the media's bias against the president and his family and what should be out of bounds.
" 'Now, attacking the first lady for her accent while reading to kids is just one small example but it's a line in the sand for me," Hannity said. "It's obvious that Melania, Barron, they are not political in their roles.' " . . .

As for Colbert...

“The only thing your mouth is good for is being Vladimir Putin’s c*ck holster,” Colbert said during Monday’s broadcast, at the end of a blistering monologue in which he also called the president a “presi-dunce” and a “prick-tator.” The comment elicited a louder than usual reaction from the studio audience.

Sean Hannity

✔@seanhannity

I will NOT support #FireColbert. I am vs ALL BOYCOTTS. He is a horrible human being, but if u don't like him change the channel.

 Sean said he considers boycotts a leftist tactic to shut down speech.