There are different enzymes to remove the glycans from the proteins or remove some part of the sugar chain. ¦Á2-3,6,8,9-Neuraminidase (from Arthrobacter ureafaciens): cleaves all non-reducing terminal branched and unbranched sialic acids. ¦Â1,4-Galactosidase (from Streptococcus pneumoniae): releases only ¦Â1,4-linked, nonreducing terminal galactose from complex carbohydrates and glycoproteins. ¦Â-N-Acetylglucosaminidase (from Streptococcus pneumoniae): cleaves all non-reducing terminal ¦Â-linked N-acetylglucosamine residues from complex carbohydrates and glycoproteins. endo-¦Á-N-Acetylgalactosaminidase (O-glycosidase from Streptococcus pneumoniae): removes O-glycosylation. This enzyme cleaves serine- or threonine-linked unsubstituted Gal¦Â1,3GalNAc PNGase F: cleaves asparagine-linked oligosaccharides unless ¦Á1,3-core fucosylated.

Reference
Wiki: Deglycosylation