It’s not necessarily difficult, but it can be expensive and will take time and effort. I found it was very rewarding though.
If you do your research properly, and have decent solder skill, you’ll be fine. The main items you’ll need are:
– temperature controlled soldering iron
– x10 magnification (for checking for solder bridges on ICs)
– x3 magnification lamp (for soldering the SMD ICs, resistors and capacitors)
– solder wick (3mm is good)
– 0.5mm soldiering wire
Skills you should search for tutes on YT:
– SMD fine pitch soldering
– using solder wick (essential for SMD fine pitch soldering)
Buying a decent temp controlled iron can mean you end up spending more than what you would for an assembled OSSC. But it is a lot of fun and you might just end up using the iron for other projects.
My 2 cents worth – if you can spare the cash, you should it. You don’t need elite soldering skills, just a steady hand and the right equipment.