Hunter's mark does need to be removed only reworked.
here is a try.
Hunter's Mark
1st level spell
Casting time: Bonus action
One target you can see or hear
Duration: 24hrs
You mark the target and focus your senses on it.
You have Advantage on Survival, Perception and Insight checks vs the target.
Once on your turn you can deal extra d6 damage to the target with an attack.
As a Bonus action or when you make Attack on your turn you can change the target of your Hunter's Mark.
Upcasting:
+1d6 damage once on your turn per spell level above 1st.
Now ranger can get extra spell preparation and extra one casting of it once per Long rest.
By limiting damage to once per turn, it does not need to have concentration.
I don't like this change at all. HM is fine as far as damaging-Gish spells go. The problem is it is a damaging spell and attaching it to a bunch of class abilities really drives the class a specific direction, one which lacks thematics and flavor and further specifically encourages weapon use on a class that is a half-caster at its base.
If you are going to tie it to class like they have done, I would like it better if you just took away the damage completely and give you advantage on all skill checks against the marked target. Keep the mechanic of moving it as a bonus action. If you did this you could also take away concentration too since you would not be getting any damage out of it anyway.