A service contract often says who may carry out a repair. That clause can decide whether a fix you make yourself, or one a friend makes, is one the paper will pay toward. Before you decide to do the work yourself or hire it out, read who the paper allows to perform it.
Three ways a repair happens
A repair can be done by an authorized repairer named in the paper, by a repairer you choose that the paper accepts, or by you. Each route brings different paperwork. The paper may require the authorized route for any claim, may accept your own work only for certain tasks, or may exclude self-performed work altogether. Find which of these the paper describes, and find the word it uses for who may do the work.
What to read for
Look for the authorized repairer or qualified person clause, any list of tasks a non-authorized person may perform, and any statement about parts, tools, or licensing. Look at the exclusions for damage caused by work outside an approved route. Note whether the paper asks for the old part back, the invoice, or a photograph of the work. The exact words matter more than the general sense of the contract.
Where licensing comes in
Some kinds of work are regulated by a licensing or permit system where the item is used, separately from the contract. Gas, electric, and water work are common examples. Check the rules for the work you have in mind before you start, and treat a licensed trade as the route for any task the local rules reserve to one. This is a general note, not legal advice on your situation.
Questions to ask in writing
Ask whether a repair you make yourself would be accepted for payment, and for which tasks. Ask whether an approved repairer must see the item before a claim, and whether that visit is a condition of coverage. Ask what evidence the paper accepts for work done by you or a friend. Ask whether work outside the paper's route can end the contract. Keep the answers with the paper.
Choosing the route
Do the work yourself only when the paper allows it, the task is within the skill you have, the item is safe to work on, and a mistake would not cost more than a hired visit. Hire the work when the paper requires an approved route, when a licensed trade is needed, or when a fault is outside what you can check. Your state's rules and the regulator named on its page on this site shape the wider picture, so start there.