Replacing just a singe gear cog?

Hi,

My 3rd gear cog is worn and seems to cause slipping out of the gear from time to time. Is is possible to replace just a single gear cog, while keeping the others (1, 2, 4) and the christmas tree untouched?

I thought about getting a DRT one. Any experiences with these?

http://www.sip-scootershop.com/en/products/gear+cog+50+teeth+3rd+gear+_40437220

Cheers,
Marcin