The "clean room" issue is bound to be less of an obstacle to you than your obvious (all respect due) lack of experience in replacing heads.

Head stack replacement is *not* easy at the best of times, and you have chosen one of the more difficult drives to work on.

If the data is critical, send it to a data Recovery Company like Salvage Data Recovery Lab Inc., 76 Progress Drive Corporate Park; Stamford, CT 06902 Chances are you will succeed. My friend has visited this company and he told me about his experience to this. He got his hard drive repaired very soon with no data lost. You can also try.