WA 380 5L komatsu Parking brake stuck on

How can you release the parking brake if it is stuck on? The loader will not move and the parking brake light stays on. There is a hose going to the parking brake that it is behind of the tranny drive shaft. Was told brake needs pressure to release it. Can I take the hose of and plug it then put some pressure to the fitting? Also can the problem be at the valve with the coil for the parking brake.

WA 380 5L komatsu Parking brake stuck on