Power steering fluid flush

I have '98 Jeep Wrangler with 65k on it. I’ve done quite a bit of abusive off-roading and everyday driving and i have a leak in the power steering pump. my mechanic’s quick and inexpensive fix was to just add power steering fluid with stop leak, as long as i dont leave the wheel turned hard for extended periods it works great. Recently i have noticed all the signs of low fluid but the reservoir is full. is it possible that my fluid is dirty and i must flush it? if so how should i do that, i prefer to not spend 80 dollars to have someone else do it.

If you want to flush the power steering system, place a drain pan below the pump and remove low pressure return hose from the pump. Plug the nipple on the pump where this hose was removed. Fill the reservior with fresh power steering fluid. With return hose pointing into the drain pan, have someone start the engine long enough so that reservoir runs empty and then shut the engine off. Refill the reservior with fresh fluid and repeat this until the fluid going into the drain pan is clean. Reconnect the hose and fill with fresh fluid.

Tester