Possible options, from easiest to hardest:

• Text inputs for X, Y coordinates for where the elements should be
  • Not ideal at all, really annoying to keep changing the coordinates until stuff fits
• A slider for X, Y coordinates for where the elements should be
  • Okay-ish solution, requires some tinkering from the user, but should be easy enough
• A 'HUD edit' mode for dragging HUD elements around to setup them
  • Really good UX for the user, no idea or time to figure out how to implement it