Citymapper - Useful transport app includes Manchester/London etc.
Train
Nearest National Rail Station: Rochdale
Trains between Manchester Victoria and Rochdale run every 30 minutes. Journey time is approximately 15 minutes.
From Rochdale:
Bus #471 leaves Rochdale Railway Station (Stop A, towards Bolton), stopping opposite Highfield Hospital. Then approx. 8 min walk.
Bus #6leaves Rochdale regularly, stopping atKirkholt, Daventry Road / near Queensway Dicken Green . Then approx. 5 min walk.
Taxi from Rochdale: about 5 minutes.
Walk from Rochdale: about 20 minutes.
Other Travel Info
Uber's pickup/drop-off point for Rochdale Station seemed to be wrong (and nowhere near the station!) You may need to change it to somewhere nearer.
For drop-off, I set it to "Worldwide Foods" cash-and-carry, near the station.
If arriving at Manchester Piccadilly:
Transpennine Express - Seems to have a bug which lists a train every minute (!!) between Manchester Piccadilly and Manchester Victoria. In fact this train only runs about once an hour.
To get between Manchester Piccadilly and Manchester Victoria (for the train/tram to Rochdale):
At Manchester Piccadilly station concourse: head down the stairs/escalator to the Metrolink tram platforms.
Tap in on the platform before boarding with a contactless debit/credit card.
Platform direction: Bury. Get the Yellow Metrolink tram line, and get off at Victoria. (4 stops).
At Manchester Victoria: Get on a Northern train service. (Direction: Rochdale/Leeds/Blackburn) (12-20 mins.)
It's also possible to get the Pink Metrolink tram line from Victoria to Rochdale, but this takes 50 minutes.