You can easily add a drain plug fixture to your pan when you have it down... I've added one to every auto I've ever owned...
Just drill a hole, clean the area with good grease/oil remover (like brake cleaner or Acetone), then sand/wire-brush the area, wipe it one more time with de-greaser, and solder in a bung into which a flush mounted 1/4" pipe plug can be inserted... WAY less messy when it comes time for servicing...
In the mean-time, clean the entire pan area thoroughly, then identify a corner or an end of the pan from which you can most-cleanly drain the fluid from the pan, without oil contacting anything other than running into a CLEAN container. Then loosen two of fasteners at that location about 1/2 -3/4 their thread length BEFORE moving on to any of the others. NOTE: The two you select should have at least one other fastener between them removed completely...
Then begin removing the fasteners closest to the two you have "1/2-way" loosened, progressively working your way to the opposite end. As you approach the opposite end, fluid should begin seeping at first, then running from the 1/2-way loosened fasteners. When this begins, stop and allow the pan to drain the fluid, until it slows to a drip, then slowly work the remaining fasteners loose, allowing the remainder of the oil to EASE out and into the CLEAN drain pan. Finally, while leaving one fastener at the opposite end of the pan from the original two that were 1/2 loose, approx 2 threads loose, support the pan at the two 1/2 loose fasteners and remove these fasteners, then SLOWLY allow the pan to drop, and the fluid to drain into the pan.
Then when it's pretty much drained, support and remove the final fastener... If you've taken your time, you should not have made any HUGE splash messes, and you will have retained your CLEAN and re-useable fluid...
HTH...