How do I drain the gear oil from a Bosch Brute Jack Hammer

Brute hammer uses special grease sold as service kit. This kit contains enough grease to lube hammer and replacement bolts that hold springs along the bottom. Check www.toolpartsdirect.com for parts and kit. Remove the lower half (tube) of hammer, also remove three bolts that hold springs and remove assembly from tube. Wash out old grease. Grease will be oil-like only when hammer is very hot, otherwise grease is paste-like. Good luck.