Yes, it is possible to rename your project in GCP. Here's how you can do it:
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Click your project in the top right
 
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Click "Manage all projects"
 
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Click your project name again
 
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If necessary, use the hamburger menu in the top left to switch to the "IAM & Admin" section
 
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Click Settings
 
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Type the new name
 
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Press Save
 
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Reload the page