Solution for restricting my uncle from obstructing our new construction

We have an ancestral property which was inherited to my dad under attested will. The same was transferred in the name of my dad in 2008 on the basis of will in society and Municipal Corporation records. Currently my dads name reflect on Property Tax Receipts, Property Card and all Society records as member. We stay on ground floor and allowed my uncle and cousins to stay on 1st floor who were already living there. Later on they acquired the terrace and kept unnecessary furniture and machinery. All the staircases are filled with unnecessary clutter. Now we want to construct a new floor for which permission is almost received from Municipal Corporation, but my uncle and cousins are not clearing the terrace to start the work and are trying to obstruct our commencement of construction. What legal action can I take against them? They had also lodged a fake complaint in police against us 2 months before saying that we threaten them to go from this property. We showed all documents to police and they also agreed that we are real owners. We want to allow them to stay on 1 floor, but want to construct 2nd floor. Please advise.