Tenant is in violation of lease and refuses to comply

[Aaron M.]

I am having difficulties with my tenant (The property is in California).  He put up a swing on a tree on the property without prior permission and is refusing to take it down.  The lease was drawn up with a California Association of Realtors (CARS) lease agreement, which states in the section on Alterations and Repairs: 

Unless otherwise specified by law or paragraph 29C without Landlord s prior written consent i. Tenant shall not make any repairs alterations or improvements in or about the Premises including painting wallpapering adding or changing locks installing antenna or satellite dishes placing signs displays or exhibits or using screws, fastening devices.

I wouldn't have minded the swing so much if the tenant hadn't already demonstrated in the past that he is quite savvy with the lease when I had requested that he provide receipts for maintenance items that the lease specified that the renter is required to take care of.  His response was that he doesnt need to provide the receipts even though he agreed to take care of the item (which he did).  He was right that the lease does not specify the need to provide receipts for maintenance items that he is responsible for maintaining but the experience caught my attention.  The other day I went to check on the property because he stated that a tree branch was hanging low and looked unsafe.  I then noticed the swing and sent him a note to take it down per the lease agreement.  He was quite unhappy about it but I am not willing to take on the liability of someone getting hurt using the swing.  The swing is "fastened" to the tree (otherwise gravity would bring them down to the ground), which to me sounds like a violation of the lease as permission was never given to put up the hammock and swing.  

I asked the renter to take down the item within 48 hours and provide photographic evidence that he has done so.  The deadline has passed and he has not provided the photos.  Can he take down the swing and hammock but then not need to provide photographic evidence that the swing was taken down because the lease does not specify that photographic evidence needs to be provided in such a case?   I am not an attorney so it is possible that the swing, for some legal reason not obvious to me, do not qualify as an "alteration or repair" as specified in the lease.  What are my options in this case?  Should I seek legal counsel?  I am not willing to take on the liability of someone getting hurt using a swing on a tree on my property.

[Frank Jiang]

Why not just get him to sign a liability waiver?  I see a lot of people quickly decrying "professional tenant" when this tenant is probably just annoyed about a landlord who's getting too deep into his personal business.