Server Administrator Job - Extending / Partition

Description

Hello,
I am the business owner of a company that runs a network of servers and provides WordPress hosting to a large number of customers.
We have one server that is very important but a long time ago the / partition was created at 10GIG. This is too small. We are fighting fires, deleting log files when the space gets used up.
So we need to extend it.
I believe this job is simple enough actually but it is also high risk, extremely high risk.
So I am looking for someone with knowledge of doing this who is genuinely confident about it. I don't nessessarily need this person to do the actual job, but I want their guidance on doing it and to be there when it actually gets done. Two minds are better than one.
So I offer £100 for this which is a payment to provide me with some backup support and knowledge doing the job.
It might be great pay for the right person and it might go really smoothly.
So we essentially want to reduce /home partition by 80GIG and increase the / by that same 80GIG.
I believe it requires a server restart so I need to let our customers on that server know.
The job would therefore be in two parts, discuss everything and formulate a plan and a time. And the second part would be to be online when the job was done by myself and offer support where needed.
I hope that all makes sense.
Thanks