Planned service changes this weekend include re-routing of Manhattan bound A trains (there will be no C train service in either direction between Brooklyn and Manhattan) over the F line between Jay Street-Metro Tech and West 4th Street, which means no Manhattan bound service at High street between 12:01 a.m. Saturday and 5:00 a.m. Monday. Your best bet for stops in Manhattan below West 4th is to go to Clark Street and take the 2 or 3, which will be running normally in both directions.
Traveling into Brooklyn is complicated on several lines. From 11:30 p.m. Friday to 5:00 a.m. Monday, there will be no F service between Jay Street and 18th Avenue, and no G between Hoyt-Schermerhorn and Bedford Avenue. Shuttle buses will provide alternative service. Also, from 6:00 a.m. Saturday until 10:00 p.m. Sunday, there will be no 3 service between Franklin Avenue and New Lots Avenue, and from 4:00 a.m. Saturday until 9:00 a.m. Sunday, no 4 service between Utica Avenue and New Lots; again, shuttle buses will be provided. If you’re coming back from Manhattan on Saturday or Sunday, Brooklyn bound R and N trains won’t be stopping at 28th, 23rd, 8th, or Prince streets. To get back from these stops, you can either take an uptown train to 14th (from Prince or 8th) or 34th (from 23rd or 28th) and get a Brooklyn bound train there, or take the 1 local from a nearby stop and change to a 2 or 3 at 14th or Chambers.
The following week, from 12:01 a.m. to 5:00 a.m. Tuesday through Friday, Manhattan bound A trains will be taking the F line from Jay Street to West 4th, so no Manhattan bound service at High Street (the C doesn’t run during these hours). Brooklyn bound N trains, which normally replace the R serving Court and Jay Street stations during these hours, will be diverted over the Manhattan Bridge between Canal Street and DeKalb Avenue. You can ride the N to DeKalb and catch a Manhattan bound N or Q back to Court or Jay, or you can use an alternate line, such as the 4 (free transfer from the N at 14th Street). If you’re going to the Upper East Side during the same wee hours, be aware that the 4 and 6 won’t be stopping at 51st, 68th, 77th, 96th, 103rd, 110th, or 116th streets. Take the train to 59th or 125th, and change to a downtown train back to the skipped stop. Finally, on Tuesday morning only, 12:30 a.m. to 5:00 a.m., there will be no 3 train service at all, although the 2 will continue to run.