Here "his head" refers to "Jesus's head." You can translate this in an active form. Alternate translation: "cloth that someone had used to cover Jesus's face" (See: [[rc://en/ta/man/translate/figs-activepassive]])
This can be stated in active form. Alternate translation: "but someone had folded it and put it aside, separate from the linen cloths" (See: [[rc://en/ta/man/translate/figs-activepassive]])