You could sue the co-owner for nuisance.  Nuisance is a serious and unreasonable interference with your use and enjoyment of the property.  Obstructing the entrance and staircase would constitute a nuisance as it unreasonably interferes with your use and enjoyment of the property.  You could take photos of the obstructing objects which would provide evidence in case they are temporarily removed.In order to get an injunction, you would have to show that damages are inadequate.  Damages are the amount of monetary compensation you are seeking.  Damages are inadequate due to multiplicity of lawsuits for repeated incidents of obstructing the path.  Damages are also inadequate because land is unique.Prior to issuing an injunction, a court will balance the competing interests of the parties.  The competing interests would be your right of access to the property versus the reason your brother claims for obstructing the entrance.  The court may issue a temporary restraining order to prevent obstruction of the entrance until a hearing at which time the court will determine whether or not to issue a preliminary injunction.  If a preliminary injunction is issued, then the court will subsequently determine whether or not to issue a permanent injunction.   It is at the court's discretion whether or not to issue the injunction based on balancing the competing interests of the parties.  A court has the discretion to require posting a bond to obtain an injunction.  However, that can be waived due to economic hardship or other issues.