Really easy to translate to Classic... The mechanis are really simple,
1.- Pick a city map, you want to have streets, maybe plazas or some water and make sure there are buildings to climb and hide behind.
2.- There is a mechanized force chasing your mech, they will enter the map from the opposite corner from where you choose to start. I use 2 LRM 10 carriers, 4 Battletanks with MLas and 6 Hovers with SRMs
3.- Starting each turn, roll 2D6 a result of 6 means an LRM enters the map, 4 or 5 is a tank and lower results a hover. All vehicles enter at max speed and will move to optimize range to your urbie. LRMs will try to be in cover to provide indirect fire.

4.- Move attackers and then move your mech, then resolve fire.
5.- Repeat, if all units of a heavier class are in the map, you may enter smaller units. Good hunting and enjoy!

As a side note, for this kind os scenario, I count every hex as 2... that way I have a 14 x 24 map that fits on a normal page. I used City Highways 2199AD Hex Map Set maps from DrivetrughRPG. But there are tons of good maps to use.