After Credit Card has been processed can i Add another $ X amount to it?

Yes I'm just looking to upgrade my client to v151

They need the ability for example if someone buys say

1 Shirt
2 Pants

Shipping and taxes = $50

They pay me using STRIP or paypal

Then I find out that they want to change there shipping to a faster way

Can I just add on $5 to there total and it would charge them - with out getting there CC again..

Every payment-provider is different, in terms of whether they allow you to do that, and what limits are imposed.

But the theory behind how to do that is the same:
a) instead of collecting final payment with each order, always get only an authorization
b) then every time you process an order for shipment, you'll manually "capture" the final payment amount. This lets you manually adjust the amount before final capture, and small adjustments like shipping methods are exactly the kind of scenario this is intended for
The built-in PayPal modules let you do this. Not sure if STRIP (whatever that is, maybe you meant Stripe?) built that into the module they provided for you.

The downside to this is that if you're selling virtual goods like digital downloads then the customers buying those things won't get immediate access if the final capture isn't done automatically.
But I'm guessing if you're selling clothing then digital downloads are probably not an issue for you.