Don't open it. There is nothing in there for such noob to be repairable. Sorry, You even don't recognize the screws. You will not be able to diagnose cause of problem, find matching donor, extract and rewrite calibration data and firmware and so on.
If you open it its gone, so why bother? There usually is a vaccum (sometimes a gas) and opening the drive will cause this to suck dust into your drive. Which will headcrash your drive.
Totally wrong. Harddrives contain normal air at ambient pressure. It is clean from dust and is actively filtered by built-in filter as the drive spins.
Hard drives are openable without using clean room and similar technology. But You must have absolutely be sure about cause of problem, have donor parts ready and have repair plan. The air must be clean and you must have steady hands. One single mistake could ruin the drive and data forever. I have repaired some harddrives myself as a last resort to recover data. It is more scary to work on drive containing precious data than disassemble rusty hand grenade.