Hello kerplunk, to start whith what year is your Berkley? and what size is the wheel? depending on the year you will likely not be able to find an exact match. also as for not being able to get to a shop there are certain tools you will need to remove the gears from the old wheel to the new wheel. also
there are lots of great sites, bike island, ebikestop, niagara,
where do you live? maybe there is a BFr near you that can help you out
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk