Hi,
For Slider :
Go to Dashboard Admin Panel >> Appearance Menu >> Theme Options >>
Slide Show Option.
Now edit Home Slide 1, Home Slide 2, Home Slide 3
And save the changes.
For Services :
Go to Dashboard Admin Panel >> Appearance Menu >> Theme Options >>
Service Option.
Now edit Service One, Service Two, Service Three.
And save the changes.
For Portfolio :
Go to Dashboard Admin Panel >> Appearance Menu >> Theme Options >>
Portfolio Option.
Now edit Portfolio One, Portfolio Two, Portfolio Three,
Portfolio Four.
And save the changes.
Please see this link for more detail.
Thanks.