Adjust the gain level on your audio interface or preamp to reduce the overall signal level coming into Logic. If you're using a dedicated preamp, it may have an output volume knob you can reduce so that the level it sends to Logic is lower.
Open your Logic project and adjust the volume on the track or bus that's clipping. Click the "Mixer" button in the control bar to switch to mixer view or click "View" on the main menu and select "Show Mixer."
Each track or bus has a dedicated channel volume fader that controls its overall volume -- locate the track or bus that's clipping and pull down its channel volume fader to reduce its volume.
Add a compression plugin to the track or bus to tame its peaks. Compression is a tool that reduces the overall dynamic range of a track, bringing up its lower levels and reducing its peaks so that the track does not clip. To add a compression plugin in Logic Pro X, switch to mixer view, click one of the track's empty audio-effect slots and select your desired compression plugin. Logic comes with a selection of native compression plugins.
Add a limiter plugin to a track or bus to prevent it from clipping. A limiter is like a wall beyond which volume cannot go. Placing a limiter plugin on a track and setting it at -1db, for example, ensures that the volume of the track can't exceed -1db. Click an empty audio effect slot on the track or bus and select a limiter plugin.