The Plugin Site

You can do this without a plugin in all versions of Premiere. Right click the piece of video on the timeline, select Speed and adjust the speed percentage. To make different parts of the same video run at different speeds just razor cut where you need changes to occur and set different speeds for each bit.

Hope this helps.

The razoring of a clip does not exactly ramp the speed changes properly, is time consuming and fiddly.

I use and recommend Twixtor which acheives this and a host of other nice things (eg motion blur). A bit pricy but worth every penny.