Hi, I installed a computer fan into my little giant and it was quite easy .Use the fan housing to mark the spots where the mounting holes will be for the fan . Drill though the Styrofoam at the location where the screws will be .Just as side note , make sure that the screws/nuts are stainless steal , or coated . Once the holes are made get a rubber or plastic spacer to put between the the fan and the Styrofoam .Put a washer between the screw and the foam and insert it through the hole and rubber washer and fan .Using another washer , slid it over the screw and tighten with the nut . I used a four inch fan , which fit right where the fan would be if I ordered it from the factory . Total cost about ten dollars including fan/ screws with nuts and washers , and plug in cord . Works fantastic . Just be ready to add water more often