I have no mechanical skill whatsoever and I put mine together just fine. Well, maybe not no, but changing my oil would be a chore.
I hear people complaining about the front take down pin all the time. When I did mine, I was expecting hell. I inserted the spring into the receiver hole. Then I used the take down pin itself to press the detent pin against the spring.
As the spring compressed, I slide the take down pin into the hole, rotated the pin so the detent indexed into the slot along the pin and I was done. First freaking try.
Where this may be difficult is if you do not have a lower receiver vice block. If the lower was loose, and you're trying to hold it between your knees, you're asking for trouble. I guess the overall theme is to get the proper tools to do the job right. This means, you'll need the proper size punches. Possibly a roll pin starter. This will reduce any receiver marring. Brownells has a lot of this.
Use the painters tape in thick layers around vulnerable areas when hammering.
Buy a quality Lower Parts Kit. No mickey mouse brands.
When I build my lower, I bought the small springs and pins in a kit from CMMG. I then replaced the individual parts with upgraded items that I wanted. Such as, I wanted a Colt buffer retainer. Wilson Combat Bolt Release. Norgon ambidextrous magazine release. LMT ambidextrous safety selector. Magpul MIAD pistol grip. I used a Timney Trigger group which simplified installation with a set of KNS pins to hold it in place. Magpul M93b collapsible stock. Everything went into a SMOS billet lower very easily.
In the build it yourself section of this forum, they have excellent step by step installation notes with photos to guide you through the installation.