Upgrading my Dell Inspiron 5567

I'm guessing you meant that you want to replace the 2 TB HDD with a new 1 TB SSD? And move the old HDD to the optical drive area?

Yes, you can do both. You may need a 2.5mm spacer/adapter to allow the thinner SSD to fit more snugly in the thicker HDD bay, and Crucial includes that plastic part with its drives. However, you may not need it. On my laptop, the drive bracket holds the new SSD so snugly that no spacer/adapter was necessary.

You can see some compatible Crucial SSDs here, though you may choose any brand you want.

You will need an appropriate caddy to fit in place of your optical drive to hold the HDD. 

You can use Acronis or Macrium or similar to backup your current drive and then restore that image to the SSD. But, I encourage you instead to perform a clean install on the SSD, which will yield a better result.

Make sure to remove the HDD from the laptop prior to installing Windows to the SSD and do not reinstall it until after first booting from the SSD.

Follow the disassembly and reassembly steps in Dell's Service Manual.
Look on YouTube for videos showing disassembly of your model. But, be cautious with them, as some use steps or methods that are not appropriate. Use the videos to add to your understanding of what to do, but follow the steps in Dell's manual.

Whenever touching components or working inside a computer, wear a grounded wrist strap, also called anti-static wrist strap, ESD wrist strap, or ground bracelet. I know many people do such work without this, but it's a cheap and sensible precaution. Rest the laptop on an anti-static mat or at least a reasonable alternative such as corrugated cardboard.

You will need a drive adapter to install a HDD/SDD in the optical bay slot. Note that there will be limitations, as the SATA interface for the optical drive is capped at SATA I speeds (150 Mbps), and that any drive that's installed there can't be used to boot into an operating system. (Use it just for additional storage). If you plan on using the 2nd HDD occasionally for storage or backups, you maybe better off purchasing an external drive enclosure, which will provide faster speeds though USB 3.0, and can be used with other computers as well.

i have also the same laptop which came with 2 tb HDD, i m planning to install 1tb HDD in this system, and put the HDD in place of optical drive so can i do it?