Hi how can i setup my rb 750 with a static ip or a dynamic ip, so i can access it from anywhere over the internet.
/ip address add xx.xx.xx.xx/xx interface=something
/ip route add dst-address=0.0.0.0/0 gateway=xxx.xxx.xxx.xxx
i ment to login to rb 750 from a different location through the internet.
its still the same. as long as the ip is globaly routable.
nimco,
is that what you are looking for?
/ip firewall filter add action=accept chain=input comment="RouterOS SSH Management" disabled=no dst-port=22 protocol=tcp
i would not know because im a new to this 
I setup a account with change ip.com to match with my ip and i also let someone try frow different location but didnot work.
What do you want to do?
To access the setup of your router from anywhere (ie winbox or ssh to the router)?
To let someone from anywhere to access to your network (ie all the computers in your local network, not the router)?
To let everyone from anywhere to access one service on one local server?
For the first option, refer to what was written above.
For the second option, you will probably need to set up a VPN (refer to the wiki)
For the last option, look at firewall/NAT
as long as someone knows the ip, eather by ip address, or some kind of DNS, it should be possible to access it from outside.
If you box is behind nat, you need to do some kind of inbound nat rule, to access it. I have a lot of devices, behind nat, and have setup a l2tp terminator, that all box will connect to, so its possible to go directly without anny nat etc.
ok, i got winbox to connect from a different internet source with the rb ip but connect with the web browser any suggestion ?
Check that ip/services allow www from anywere
Check that you opened your :80 port from outside (/ip firewall filter add action=accept chain=input comment=“RouterOS www Management” disabled=no dst-port=80 protocol=tcp)
ok i will
Setting up Router Board 750 with a static or Dynamic IP address will only allow remote access between computers which are directly connected to same router Ethernet ports i.e. Computers on same networks. In order to access computers over internet using RB 750, you need to either deploy on premise remote support appliance such as Bomgar or RHUB appliances or can even use various remote support tools such as logmeinrescue, gosupportnow, GoToMyPC etc.