What is the significance of the priest changing his garments?
Leviticus 6:11 (ESV)
11Then he shall take off his garments and put on other garments and carry the ashes outside the camp to a clean place.
By changing his garments, the priest would maintain the distinction between the holy and the unholy. Furthermore, the holy garments are not to be defiled by being worn outside the tabernacle.
11 Then he shall take off his garments and put on other garments and carry the ashes outside the camp to a clean place.