You can't do much now. You've opened the drive, so dust and other particles are now on the platter and will cause further damage to your data. Employees manufacturing hard drives wear equivalents to space suits in a hard drive factory in clean rooms to prevent any particle contamination in the drives.
The original clicking was due to difficulty reading the platters. Now it would have been possible to recover the data because it was minor errors and remap around the errors. The damage caused by dust and other particles is much larger, and when it catches under the head while the drive spins, it will scrape more data off the drive.
You will now need an expensive technician to forensically recover your data, or call your drive a total loss.