Is there an easy way to disconnect old wires and re use this? If not, can you cut old wire and use other holes?

By pulling and twisting each wire you can pull them out one at a time. For stranded wire we do not recommend re-using the connector as strands break of inside. For solid wires you can reuse the connector. If it looks to be damaged in the process use a new one. Hope that helped Ron at ron.kipper@idealindustries.com