John Gill Commentary Deuteronomy 2:22

"as he did for the children of Esau, that dwell in Seir, when he destroyed the Horites from before them; and they succeeded them, and dwelt in their stead even unto this day:" — Deuteronomy 2:22 (ASV)

As he did to the children of Esau which dwelt in Seir
He did the like things for them as he did for the Ammonites:

when he destroyed the Horims from before them :
which is repeated from (Deuteronomy 2:12) , other instances of the like kind being here recited:

and they succeeded them, and dwelt in their stead, even unto this day ;
(See Gill on Deuteronomy 2:12).