I bought a cheap ham a few months back that came the same way. Like you, I got about 3/4 of it off before finally throwing it on the smoker. After about two hours I was able to remove the remaining amounts.
Funny thing, it turned out to be one of the best hams I've ever had.
Backwoods G2 Chubby, Weber 26.75 OTG, UDS with Weber rotisserie, Blue Weber Performer with gas assist, Smoke Hollow elec. smoker, SJG mini-WSM, Weber Go Anywhere, White thermapen, Blue-Backlight thermapen, Maverick ET-732 x 2, BernzOmatic JT-850 Weed Burner, BernzOmatic TS8000BZKC Hand Torch and the New LooftLighter.