thank you. The first step would be to determine the precise nature of the right of way and the extent of land over which it is enjoyed - usually referred to by way of a plan.
From what you describe, if the wording you have typed above his precise, the right is a right of way on foot only over the yard - I am not certain of a specific route is defined or if the right-of-way is expressed to be over the yard generally. Unless there is a contrary intention in the wording of the right of way, the decision in the case of Hammond v Prentice Brothers Ltd  1 Ch held that in the absence of special circumstances, the right of way shall be construed so as to secure all that was necessary for the reasonable enjoyment of the property to which the ROW was granted and that words in a grant that list people who can use the right of way (such as tenants, visitors etc) are generally regarded as illustrative and not restrictive. accordingly, my initial belief would be that the right-of-way is likely to be sufficient for guests to use it but this view should not be regarded as a definitive interpretation of the law as this would require counsel's opinion.
however, from what you describe, the right is a right of way rather than a right of amenity in relation to yoour yard and as such, the rights use should be for the purposes of access and egress from the relevant properties are not for any other purpose. as such, you can consider in the first instance writing to the owner with a cease-and-desist letter advising him of the use to which his guests are making of the yard and requiring that both he and his guests cease and desist in such use failing which you will seek injunctive relief against him for trespass together with costs.
You could go on to say that you are willing to work with him as regards ***** ***** that can be taken to ensure that his guests are aware of the limitations of his property rights but your concern at present, that there is either an active disregard or at least a negligent disregard as regards ***** ***** rights and you would ask him to make contact with you in this respect within the next 14 days with an undertaking to cease and desist trespass onto your land failing which, you reserve the right to take steps in relation to injunctive relief in the County Court without further reference to him.
In order too apply for an injunction, you would need evidence of the infringement of your property rights that you describe-such as photographs together with dates and so on and apply using the following form: