Replacing the memory in your computer will be necessary if a memory test has confirmed that your RAM has experienced a hardware failure of some kind.
Important: Most motherboards have strict requirements on the types and sizes of RAM and which slots on the motherboard and in what combinations that RAM can be installed. Please reference your motherboard or computer system manual before purchasing memory for your computer.
Answer: To replace the memory in your PC, you'll need to physically remove the old memory and install the new memory.
The specific steps necessary to replace the memory in your computer depends on whether you are replacing the RAM in a desktop or laptop computer.