Method 1 - Manual removal (requires very basic CSS skills)
Step 1.
Go to your AdminCP -> Customization -> Themes -> YourTheme -> Edit HTML and CSS

Image 1: Themes

Image 2: Edit HTML and CSS
Step 2.
Switch to the CSS tab and search for a file named "custom.css". The search will find the correct file (there is only one custom.css).

Image 3: Searching for custom.css
Step 3.
Make a new line in your custom.css file by clicking in the textbox and hitting Enter. Then, paste the following CSS code:
[data-pagemodule="forums"][data-pagecontroller="index"] .cForumHeader h1.ipsType_pageTitle { display: none; }
It should look like this when you're finished:

Image 4: Paste code into textbox
Step 4.
Lastly, click the "Save" button.

Image 5: Save button
Upon refreshing your site it should now not show the "Forums" title.
Method 2 - Automatic removal
For this method you simply need to download this plugin and upload it to your site. It will handle the the entire removal process.
I hope this tutorial helped you

If you need help with anything specific feel free to message me on Discord. My tag is cold#0001