To change the JQuery you can go to the default ScriptManager settings by selecting Administration
-> Script Manager
-> Script References
and change the default path, but it is not appropriate to change it because Sitefinity is stable with this particular version of JQuery and the tests we have made are connected with it.
In order to avoid your problem you can change the JQuery in your master page using the following source code for example:
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items