The word "them" refers to the hairs. Possible meanings are 1) the hairs were long enough so Ezekiel could tie them or 2) Ezekiel was to sew the hairs or otherwise attach them 3) Ezekiel was to place the hairs loosely in a fold of the garment.
Possible meanings are 1) "the cloth on your arms" ("your sleeves") or 2) "the end of the cloth on your robe" ("your hem") or 3) the fold in the garment where it is tucked into the belt.