@Supersuperleeds
You've got a choice on the square you were interested in.
1) You can ride down the road to Pasture Farm - it is signposted as a private road. However these are often bridleways as well where cycling/walking and horseriding are allowed - which you could use as an excuse if needed because there is a bridleway that goes to the farm just not from this direction. You do need to go nearly up to the farm though.
Other options are the Red Lane bridleway north out of Welby - 800m, Track A to the east of Welby - 200m North on a track to the side of a field (best in dry conditions), Track B - a 100m walk along the edge of a field and a farm garden.
I think I'll end up using the bridleway when conditions allow as I try to use a permitted route where possible.
@tallliman
I need the 2 squares between Aisby and Dembleby as well, when the ground drys up I was going to approach the western square from Aisby and the eastern square from Dembleby in the hope that it would be easier to not venture too far down the bridleway