For drive issues, this is easy. Have a stack of replacements on hand and just open a "remote-hands" ticket with the CoLo provider to swap out the drive. This can usually be done in 1-2hrs from opening the ticket.
For server issues; again, pretty easy. Just use iKVM/IPMI and iPXE to diagnose a faulty server. Again, using "remote-hands" from the CoLo provider can help fix problems if your staff does not have the skills.