Hi Iiyazza,
As you are trying to delete the layers in PDF, sorry to say it is not possible in Adobe Acrobat Reader DC application.
Reader DC is a free software and used for viewing, printing, signing and annotating PDFs.
You will need Adobe Acrobat DC subscription for this.
If you already have Adobe Acrobat DC, you may refer the steps mentioned in the link provided below:
PDF layers, Adobe Acrobat
Delete a layer in a PDF in Acrobat
Acrobat DC - Delete Layers
How to remove layer from the New Adobe Acrobat Pro DC!
Hope that answers your query.
Let us know if you need any help or have any questions.
Regards,
Meenakshi