This is all very double dummy, but i think you can make it looking at all the cards as follows.
Win the HA and ruff a heart high. Play two rounds of trumps. Either west keeps the C2 or he doesn't.
a. He has the CJ (or T) left.
Now you can play a club. he has to win and give a ruff sluff. You ruff on the board, pitching a spade. You play a Diamond ( east has to split) to your A or K.
Now you cash your last trump, throwing a diamond from the board.
Everyone is down to 5 cards, and east must unguard either spades or diamonds, so u have the rest of the tricks.
b. He throws the CJ and CT, keeping the C2. Now you cannot force him to win the third club, but instead you can overtake the C8 with the C9 and play a Diamond, east splitting.
You can cross to the board with the C4 to the C7.
Now everyone is down to 6 cards and East must hold 3S and 3D. so you can finesse Diamonds , cash the other high diamond and exit with a diamond loser to East, who will have to break spades for you, again giving you the rest of the tricks.
Someday GIB will play like this. Or not