If it is simple reed valves and if you can find the valves (Tractor Supply keeps some reed valves) then it should not be hard to fix. Be warned however these compressors are generally considered to be of the "throw-away" variety and if the valves are not one of the common types they may be hard to find, any parts for this thing may be hard to come by. First MAKE ABSOLUTELY SURE!!! there is no pressure left in the tank and then remove the head from the pump, the valves should be thin flat flaps looking kind of like a feeler gauge and should be simple to replace if you can find the new ones. Take the head off and let us know what you find, a pic might help.
Make SURE there is no pressure left in that tank before starting to work on this thing because even a small compressor like that can hurt you if you disassemble certain parts with pressure on them.