The replacement can go in with either polarity.
The banded end on the old caps denoted the "outside foil", which was usually connected to lower impedance side of the circuit. This somewhat improved the shielding/reduced hum in sensitive circuits.
If you are dealing with really sensitive circuitry (high gain audio preamps), it is possible to determine which end is which using a scope, but for recapping a TV chassis, it generally isn't worth the effort:
http://www.aikenamps.com/OutsideFoil.htm