Rotting tree: tenant willing to cut down...liability?

[Robert L.]

There is a rotting maple tree on my property that could be a risk to the neighbor's house or livelihood, not to mention the risk to my tenant and my property.  Well, the tenant says he is VERY experienced to cut it down and just needs to rent this equipment from Sunbelt  Rental for $300 and is willing to sign any waiver that says owner is not liable if he gets hurt. 

I feel it could still be risky if he gets hurt from doing this, if the landlord allows or even pays him for the labor. Even if he signs a waiver or agreement NOT to sue the landlord, would you hire a tree company no matter what for a higher price or is it safe to let tenant do this work signing proper disclaimers/waivers that landlord is not responsible.

Thanks in advance,

Rob