We describe an experiment to interface and characterize silver nanoparticle (AgNPs) aggregates that are self-assembled and plastically deformable on a thin gold (Au) film deposited on glass substrate. The electrical characterization is done using an electrical nanoprobe attached to a nano-manipulator inside a scanning electron microscope (SEM). Electrical current-voltage (I-V) measurements are made between the electrical nanoprobe in contact with the nanoparticle and the Au film. The Ag nanoparticles have diameters ranging between ~200-800nm and are self-assembled on a thiolated 100nm Au film. Application of a contact force via the nanoprobe even after substantial particle deformation reveals initially a small non-linear current. Upon current annealing through Joule heating, significant improvement in the electrical contact at the AgNP/substrate interface was observed. This is most likely based on bonding of the AgNPs to the Au film after passage of a high current. The need for such an annealing/sintering step will be critical in forming good ohmic contacts at ambient conditions during transfer printing of semiconductor micro/nanopillars.