Obtain technical training in simple electro mechanical assembly/disassembly
Obtain MCSE training
Seek Business training
Negotiate agreements and accounts with parts suppliers
When the machine arrives....
Explain T&Cs to customer to set expectations particularly with respect to Cost, Time and any warranty offered
Seek trouble statement form customer
Record necessary information including customer contact details etc.
Make initial assessment of problem (confirm customer trouble statement - or develop more accurate one)
Use analysis to determine most probable cause
Test hypothesis - make repair - confirm machine working
If not working jump back three steps
If working set machine aside for soak test for appropriate period
Contact customer to confirm repair and advise of costs
Produce job sheet outlining actual problems discovered and work done to resolve them
Exchange machine for payment
After one or two weeks contact customer to ensure machine still operating ok.
Put customer details on database for mail shots / follow up and annual greeting card recognising customer's specific cultural and religious preferences.
Smile throughout and be patient and honest in dealings with customer - if you make a promise strive as hard as you can to honour the promise and if unable to, contact the customer to explain the situation before the customer contacts you.
There may be other things but these are the few that spring immediately to mind.
Good luck...
Peccavi, July 2009