In Elegoo Slicer , the usual way to change what filament an object uses is to assign that object or filament profile in the slicer, then reslice the model. For a mid-print color swap, you typically add a pause or filament- swap at the layer where you want the change, after slicing and in Preview.

Change the filament profile

  • Open the model in Elegoo Slicer.
  • Go to the filament section and make sure the filament you want is added there.
  • Select the object or its filament assignment, then choose the correct filament profile.
  • Slice again so the G-code matches the new filament settings.

Swap filament during a print

  • Slice the model first.
  • Open the preview and use the layer slider on the right.
  • Find the layer where you want the change.
  • Right-click and choose Add Pause or Add Filament Swap if that option appears.

Important detail

Some users note that the filament-swap option only appears after you add a second filament in the printer/filament setup first. If you only need a manual swap, a simple pause is often enough.

Printer-side load and unload

If you mean physically changing the spool on the printer itself, the printer menu usually has unload and load options under the extruder or filament section. That is separate from changing the filament assignment inside the slicer.

TL;DR: Add the right filament in Elegoo Slicer for the object, then reslice. For a color change mid-print, use Preview, go to the target layer, and insert a pause or filament swap.