Transporter T4 coolant drain location?!

[johnsbegood]

Hi guys. Need to do a coolant flush on my T4 2.5tdi transporter. Just wondering if anyone knows the location for the nut/tap to drain the engine block?! I was going to loosen the lower rad hose to drain that side but would like to know how to drain the engine side. I could drain rad, refil with water, run engine to dilute trapped coolant in block then drain rad again but I want to do a proper flush of block and rad. I've heard there is a bolt by the fuel pump that's a drain hole for the engine block.