We'd need to know your motherboard to give you specific instructions on how to change boot priority, however the process is pretty much the same, just a different look:
Go to BIOS > Boot > then Change the Order.
For clean installing windows, follow this guide entirely: https://forums.tomshardware.com/faq/how-to-do-a-clean-installation-of-windows-10.3170366/
This includes removing the HDD and clean installing onto the SSD. Then you can replug in the HDD and do what you will with it (clean wipe it for example).
If you haven't opened the laptop, how are you installing the SSD?I can’t remove my hdd because my laptop is really hard to open. Will windows ask me on which disk to be installed when i clean install it? Maybe i can just reinstall it completey and then choose my sdd as the instalation disk
I opened it to install the sdd but i closed it now. I struggled a lot to open it. Will my method work?If you haven't opened the laptop, how are you installing the SSD?
You will ideally want to remove all other drives otherwise it can cause some issues.