Winbox might be easier for you ?
Help on terminal:
F1 = help on current command
TAB = (usually) will display available options at that point.
It's in the documentation
https://help.mikrotik.com/docs/display/ ... Management
In this specific case you would have to use
/ip pool edit 0 ranges
then edit screen will appear
and ctrl-o to save&quit as displayed on screen.
Personally I would use print , remove and then add.
Ex. changing pool on ETH5:
[xyz@hAPAX3-1] /ip/pool> print
Columns: NAME, RANGES
# NAME RANGES
0 VLAN2 192.168.2.100-192.168.2.254
1 VLAN99 192.168.99.10-192.168.99.19
2 VLAN20 192.168.20.100-192.168.20.199
3 VLAN10 192.168.10.100-192.168.10.199
4 ETH5 10.20.20.2/31
5 VLAN30 192.168.30.100-192.168.30.199
/ip pool remove 4
or
/ip pool remove ETH5
/ip pool add name=ETH5 ranges=10.20.20.4/31
Winbox is a lot easier for such things, though ...