Changing PLCs

Hello, folks!
FOA, I'm not a native english speaker, so bear with me...

I've recently been asked to change the PLC controlling a fiber painting machine. The problem is I've never done this before... That being said, I need your help to assure I won't screw up!
Both PLCs are Siemens:

• Old: CPU 314 IFM (6ES7 350-5AE02-0AB0)

• New: CPU 314C-2DP (6ES7 314-6CH04-0AB0)

The rack currently has the following modules:

1. FM 350 Counter (6ES7 350-1AH01-0AE0)
2. DI32xDC24V (6ES7 321-1BL00-0AA0)
3. DO16xRelais (6ES7 322-1HH00-0AA0)
4. DO8xRelais (6ES7 322-1HF00-0AA0)
5. A04x12bit (6ES7 332-5HD01-0AB0)
6. AO4x12bit (6ES7 332-5HD01-0AB0)
7. AI2x12bit (6ES7 331-7KB01-0AB0)

A CP 343-1 (6GK7 343-1EX30-0XE0) will be added.

I know the CPU 314IFM has special integrated counter inputs (used in the program), and so does the CPU 314C-2DP, but they are configured and used differently...

What should I be careful with? What's the standard procedure (if there's one)? I've already configured the hardware to address the inputs and outputs like the old PLC did, but something tells me that's not the whole story

https://support.industry.siemens.com/cs/document/13337010/s7-300-upgrade-check-tool?dti=0&lc=en-WW

S7-300 Upgrade Check Tool - Link above.

This may be of assistance.
Regards,

This tool compares SFCs in both CPUs, doesn't it?
Besides, I tried downloading it... Couldn't use it in my machine because it won't detect (and believe me, I tried a lot) the installed Step 7.