What?
If he does an apprenticeship (which are like rocking-horse cack so a non-starter of an idea) he will be on slave labour wages AND he will have to go back to college and do the levels 2 and 3 again. Cost around £60k in lost wages and 3+ years.
He doesn't need to do that, he needs to get a CSCS/ECS card, an IPAF, his 18th edition if he's not already got it.
Then he needs to get work experience however he can get it. Then look at 2391 and the NVQ3.
I recommend lying on CV to secure 'mate' work to start off with. ~£13-14 to start instead of £4.81. If you know how to wire stuff up and do the basics like pulling, marking and tying off cable, drilling and plugging properly, fishing cables, all that good stuff, then go for that route. I was a builder for years and did bits and bobs of electrics, move a socket here, wire up a kitchen there, but when it came to wanting to move into electric full time i simply 'embellished' my CV to make out like it was mostly what i did. All is fair in love and employment - employers will use you up and spit you out if it's financially convenient for them. As long as you can do what you're claiming you can do, then lie about having tonnes of experience doing it.
I'm working with fully qualified sparks on a solar farm at the minute, and they don't know how to cut cable the right length, mark up properly, do containment, dress in cables or put the right MC4 on the right leg. They're on £22 an hour, absolutely stealing a living at a grand a week. Have some confidence, do the basics well and you'll slot right in.