Can you see from where the fluid is leaking?
I recently had a leak from the fluid reservoir where the screen and headlight wash pumps push into the rubber seal that are integral to the filters in the fluid reservoir. In my case the seals were hard from age and probably a little damaged after I removed and washed the fluid reservoir of the gunk that had formed following the mix of BMW and Halford brand screen wash.
If it is leaking from these rubber seals, it's a DIY job to remove the fluid reservoir and replace the filters - search for instructions. The only tool needed is a flat blade screwdriver to prise open the clip on the fluid reservoir to lift it out.
If it's not the seals - since you say the fluid reservoir appears to be full - have the pipes to the pumps disconnected and leaked fluid? Again these are easy to pop back on, but make sure the 'lock' has been engaged to prevent them coming off again. If I remember correctly there is a ring that needs to be turned through 90 degrees that is near the pipe end that pushes on to the pump outlet.
Cheers!
Andy