Some pry the seal out of the timing cover and that should give you enough room to get behind the broken part to pull it forward.
Others drill a couple small holes in the remaining peice of the dampner and install sheet metal screws in the holes and pry against the heads of the screws to get the broken portion to slide off the crank.
I had the same broken harmonic balancer piece left on the crank issue.
With a sharp tipped nail punch-marked four evenly spaced holes into the aluminum outer edge.(staying close to the outer ring sleeve) These four marked starter holes help the drill bit from veering off and scratching the crank.
Drilled 1/4" deep, parallel to the crank, using a small 3/32" diameter bit.
Took a large 2" washer with a 7/8" center opening and drilled four 3/16" holes into it spaced-out in the same manner as holes drilled in broken balancer piece.
Then inserted 1-1/2" long screws through washer and into broken balancer piece.
Finally used a 3-jaw puller to pull on the washer and removed.
(Keep in mind to avoid and not damage timing cover front seal if your reusing. These seals are hard to remove sometimes.)
Bravo, and you can work on my SC ANYTIME, That's one sharp tool, I love it when I also come up with solutions to a problem like that, sort of reaffirms my abilities as an old greasemonkey. cheers and beers, Frank H.
Double duty- broken H_Balancer and SC snout seal puller
Time will be well spent if you decide to use the washer method. It could also be used as a SuperCharger front snout seal puller. So, it will serve double duty as a broken H_Balancer on crank and a S_Charger front snout seal puller.