She bollockses the presentation by skipping the important slides at the last minute.

She lectured on bollocksology with surprising seriousness, arguing that examining nonsense reveals cultural truths.

I bollocksed up the presentation by forgetting my slides and running out of time.

He bollockses up every presentation because he forgets his slides.

By repeatedly ignoring the test results, she was bollocksing up the experiment and wasting months of work.