I recommend doing this cache as part of a circular walk (well, more of a lollipop shape really). OS Explorer 217 is handy.
Starting at Bridges you can park at "The Bridges". (Can you see a theme developing?) Head east up the road and past the youth hostel. There is alternate parking in a lay-by after the hostel if you do not intend to sample the pub fare.
Follow the Shropshire Way north east from the road up the valley. Your can detour to Ratlinghope - Shropshire Church Gems at the ford (after the fourth stile - N.B. all stiles are dog friendly) and there after continue towards the farm at Lower Darnford then head north up the hill towards the cache area. Follow public footpaths to Upper Stitt Farm, then take the road south west to the phone box. A footpath leads back over the hill to Darnford Brook. You should now know the way back to Bridges.
The whole route is 8.3Km and takes about 2 hours at a very steady pace. Just enough to work up an appetite :) Local ale and excellent food can be found at The Bridges.
If you are in a rush, there are other ways to reach the cache. I will leave the route planning to you. However, I did want you to stretch your legs a little!