Here's video how to change coolant on GTS300, same method for 200 and 250 too.

Tools I used:
Tools I used:
Coolant - https://amzn.to/2KrkT2y
1/4 clear tubing - https://amzn.to/2wHDyVU
Phillips #2 screwdriver - http://amzn.to/2fgdZDL
Torx T25 screwdriver - http://amzn.to/2FoTZtv
5/16 wrench - https://amzn.to/2rFSZbw
Funnel (short) - https://amzn.to/2HY4m6g
Water Distilled - get at grocery store
Pan - cut half off of drink jug
Plastic bag / garbage bag
Paint / electrical tape - http://amzn.to/2FEeQH2
Old sock / rag
Bleeder valve o-ring #297027 af1racing.com
Water pump cover o-ring #485080 af1racing.com