Question about a panel change out(old FPE)?

i have been asked to change 4 federal pacific electric panels. they are probably just going to be subpanels mainly, just one smaller main. i have never done a panel change before, but have installed and wired several panels in a clroom environment. my "main" question is how will i disconnect power to the main, will the owner need to schedule an appointment with the utility, and if so, will i need to be involved? my second question is, how tight should i torque the lugs? i have 10mm and 3/8 inch allen wrenches, will these be big enough? i have smaller. my final question is what if i run into knob and tube? is it legal to terminate K&T in a new panel, if not, how would i do it?