A) You carefully attempt to unwrap excess wires and other components from the portal rings.
Dexterity or Disable Device
B) With the scrap all across the room and help from the console, you scrounge up materials to dampen the portals’ power.
Knowledge (engineering) or Survival
C) There are many eldritch runes scrawled around the portals, which appear to conjure hotter flames than usual. You carefully find and scratch out the most important ones.
Knowledge (planes) or Spellcraft
D) Large power cells have been improperly fit in the portal housings to boost their output. You use brute strength to wriggle them out or find a way around magical adhesives holding them in place. As less integral pieces, you could also smash them, but it could be perilous.
Strength or Use Magic Device, or just melee damage