Your generator must power the outside "plug"...presuming you have one (for the patio lights, etc.)start the genny and put an extension cord on that.
No mods needed. It worked for me with "Sandy"...power went out for 4 days. 50 ft of 12 Ga. extension cord...alternate between the lights & TV...the kitchen fridge and garage freezer. Went outside to use the propane stove and bar-b-q grill. (All electric house). We survived just fine.
Then....I bought a 8,000 watt generator and had an electrician install a transfer switch. SO MUCH better than that PITA(but workable )extension cord. method.