You want to rethread the spokes where the 'spoke head' faces in. Circled in red. The green ones face out.
So follow each of these spokes up to the nipple, undo the nipple and rethread it going over, over, under, as per the red line, and the video series.
However... because the spokes will already have tension, you should loosen all the spokes before you start fucking with them. Do this SLOWLY. 1/4 of a turn on *every *spoke, one, by one. Then once they are looser, 1/2 a turn, then once they are really loose you can start rethreading all the ones that have the head facing inwards.
Altho it is not going to be hard, it will be time consuming. I enjoy building and truing, some people don't.
RE truing, no, you don't need to take them to a shop. You can true them yourself using your frame. This side of wheelbuilding is well covered elsewhere on the forum, so have a search and a read.
As I'm sure you'll find after doing some reading, one of the keys is doing it all slowly and bit by bit. So don't jump straight into it, do some prep.
Oh and you might want to get some tape to keep track of the spokes.
You want to rethread the spokes where the 'spoke head' faces in. Circled in red. The green ones face out.
So follow each of these spokes up to the nipple, undo the nipple and rethread it going over, over, under, as per the red line, and the video series.
However... because the spokes will already have tension, you should loosen all the spokes before you start fucking with them. Do this SLOWLY. 1/4 of a turn on *every *spoke, one, by one. Then once they are looser, 1/2 a turn, then once they are really loose you can start rethreading all the ones that have the head facing inwards.
Altho it is not going to be hard, it will be time consuming. I enjoy building and truing, some people don't.
RE truing, no, you don't need to take them to a shop. You can true them yourself using your frame. This side of wheelbuilding is well covered elsewhere on the forum, so have a search and a read.
As I'm sure you'll find after doing some reading, one of the keys is doing it all slowly and bit by bit. So don't jump straight into it, do some prep.
Oh and you might want to get some tape to keep track of the spokes.