Depending on your footage, this could be very difficult. There are very few things in AE that you can do without a solid understanding of the fundamentals. Todd Kopriva from Adobe has created a page about getting started with After Effects.
A couple questions: what version of AE are you running? Can you post a screen shot or a video of your footage? Is the shot locked down, or moving?
There’s a tutorial here on the COW about simple object removal. It’s several years old now, but goes through many of the fundamentals for an effect like this.
Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
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