I need to know where to add hydraulic fluid in a John Deere 2010

There are several places for checking and adding fluid. What seems low, the bucket hydraulics, or the drive hydraulics (ie: tranaxle)

Visit the on-line store, know as reliable-store, they have the repair manuals. I'm sure you will get the solution of your problem.
Best Manuals

JD Mower Maintenance - YouTube

? 16:56
https://www.youtube.com/watch?v=RYeP_QLhsoU
Mar 31, 2013 - Uploaded by GreenMachine757
Doing routine maintenance on my John Deere 757 zero turnmower. ... DIY Mower Seat Repair - Garden Tractor Seat - Zero Turn - eXmark ...

John Deere Tractors Information - SSB Tractor Forum

www.ssbtractor.com/wwwboard/messages6/
Service Transmission - John Deere Ag - New Equipmentmanuals.deere.com/cceomview/OMM144042.../OMM144042_D010.ht...DO NOT mix oils. These tractors are equipped with a hydraulic wet disc PTO clutch.... DO NOT use type "F" automatic transmission fluid. John Deere Low ...JD 445 Rider Mower Issues - Need Help Please - GardenWebforums2.gardenweb.com > Garden Forums > TractorsNov 12, 2009 - But I've read a lot of threads hoping to read about my issues, and was ...What tools I don't have my friends do, and both are real mechanics, big Deere fans ....it steer hard due to lack of fluid in the hydraulic steering cylinder. ... You may need to add fluid, run the tractor around a bit, and then check it again.

You just go to the link I attached I'm sure you will get the solution of your problem.
John Deere 310G

Where can I purchase a John Deere 430 Lawn Tractor Radiator?

yep there is!

There is a round clear glass usually around pto shaft if is completely clear then you are low on hydraulic fluid. HyGaurd hydraulic fluid is best for john deeres. Yes only bought from dealer or amazon, e-bay. It is guaranteed to last for hrs before needing servicing.

The three point hitch raises with hydraulic pressure. When the hitch will not raise the first thing to check is the hydraulic fluid level. If it is low add hydraulic fluid to the proper level as stated in the owner manual.

I would suggest you find a JD dealer and buy a manual if you want to do the maintenance yourself. You can also do a Google search and find manuals.

I would also suggest you completely drain the old hydraulic fluid and replace it with new fluid and a new filter if it has not been serviced any time in the recent past.

The symptoms you describe can be low fluid and/or a clogged filter. If you or anyone else has run the tractor too long and it has low fluids and/or a clogged filter, you can damage the hydraulic pump and that can get costly.