Upgrade Methods

Would you mind clarifying the method for upgrading the program.
I have the CD. Rec’d it on Father’s Day.
It would help me to have very detailed instructions and screenshots at my level of computer literacy. Perhaps I’ve missed the detailed instructions somewhere.

I understand we get a max of 2 download installations with each purchase, but it appears that in upgrading, I will be fully downloading again and I will use up my remaining one download. Is this correct.? I might need the remaining one download if I have a system crash.

To be specific, it appears to me that I open the original email with download instructions. Then access the download. At that point, do I save the new program somewhere else and in fact have 2 separate programs, or do I save it to the same place as the existing program, which hopefully will prompt my computer to ask me if I want to replace this with that, or will it ask me “is this an upgrade ? ” … wish I knew.
Will I lose existing data if it becomes the new program ?
Does the update merge with the previous version ?

To be fair, it’s probably one of 3 things.
I’m not computer literate enough for this software.
I’ve missed something obvious somewhere.
The instructions should be more detailed.

Frankly, I’ve had enough computer problems lately and prefer to avoid them now rather than “forging ahead and see what happens “. I guess I’m weary of struggling with software.

Any assistance would be appreciated.

Regards
thecrest