About how much will it be if i fix the oil gasket and how is a transmisson fluid change?

It is probably not the oil pan gasket. If it is engine oil, it is more than likely the rear main oil seal. If it is trans fluid, it is more than likely the front trans seal. Price depends on the difficulty of the repair. Between $60 and $700 I would guess. It depends on the make of the vehicle, and the shop doing the job also. Dealer shops are outrageous in price per hour.About how much will it be if i fix the oil gasket and how is a transmisson fluid change?
Your question is unclear! But, if you have to fix the tranny oil gasket, you'll have to drain out the tranny oil, which is done by loosening all of the bolts, taking out 4-5, letting the pan drop down, and having the tranny fluid run into a catch pan! After all or most of the oil has run into the catch pan, take out the rest of the bolts and remove the oil pan. Then remove the oil filter, install a new filter, and pan gasket if supplied, and refill the tranny with the proper transmission oil! Careful--if you use the wrong type of oil, you'll be in big trouble! Check in the car book in the glove box-it'll tell you what type oil to use! As for cost, i can't tell you-you'll have to ask at a transmission shop. If you don't have a jack or tools, don't worry about the cost--have them do it, and pay the bill! You don't want a botch job done by an inexperienced person (you), which might cost more than you try to save by doing it yerself!