How should I handle a planned power cut so I don't end up on a slower profile

[#1]

I've got the electrician coming in to do a job on Monday and he will want to turn the power off.  Since I started using Plusnet on Sep 12th, I've been very happy with the rock solid 72.8Mbps profile I was put on and I *really* don't want the exchange slowing it down because it interprets the disconnection as the result of an unstable line.  Does anyone have any recommendations about how to handle it?  Presumably I should leave the modem unplugged for an hour or something but I wonder if there's anything else I should know about.

[#2]

Turn the modem's power off, rather than unplugging the phone connection. Leave off for at least 30 mins.
That's based on hearsay, but is the safest set of instructions. However, if the cabinet sees less than 10 disconnections in one day, you should be OK.

[#3]

drop your session in the router gracefully first as well, using the disconnect button (if available), then as WWWombat says power everything down before the power is off.

[#4]

Thanks to both of you!  I really appreciate the advice. 

[#5]

FWIW, the absolute opposite happened.
Overnight after plugging the modem back in, the profile was increased from 72Mbps to 75.2Mpbs.
Hopefully it stays that way.  I always seem to get throughput about 3Mbps slower than the profile, so I'm getting 72Mbps all over the house now whereas previously I was getting 69Mbps.

[#6]

Good to know the advice worked for you and you even managed to get an increase in your profile.