Montana shared that Clark had asked him to speak at his funeral before he died.
"I had a few choice words for him, which I can't say in church," Montana said.
He also noted, "I'm not one for usually writing things down, but I won't lie, this is probably one of the toughest things I've ever had to do."
Other family and 49ers legends spoke at Clark's memorial service. Click here for a look.
STORIES & VIDEOS ABOUT CLARK
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