Try installing ViperOne. It's noob friendly, let's you remove bloatware, and change the boot animation in tweaks. If you wanna keep your ROM, just disable any unwanted apps. As for the boot animations. Follow these steps:
1. Get Root browser
2. Download a boot anim (1080x1920)
3. Rename it to hTC_bootup.zip (hTC_down.zip for down anim)
4. Copy it to system/customize/resources, and replace. Make sure you have write permissions.
5. Reboot, and test. If it doesn't work, try installing with TWRP's file manager.
IMO, getting ViperOne is easier. Good luck dude.
Sent from my HTC One using Tapatalk
- HTC One M7 Silver
(2013) running ViperOne 5.8.0
- HTC One V Black
(2012) running Ignorance V4