If anyone is familiar of the underbody of the Subaru Legacy GT. Tried to do an oil service on the car yesterday but there are 3 hex/philip head screws that hold the plastic underbody along with some clips. WD/40 or no persuasion helped to get them off. They are no long hex heads anymore . Any tips to get them off to get at the oil filter? I didn't have heat and plus it's fixed to plastic might not be the best option. Thanks