How can we see other galaxies?
Get a star map and a powerful telescope.
Select a dark night with out Moon and no clouds and light pollution from city lights..Look at star map where galaxies are marked.
or you can use google sky or any other planetarium software.
Astronomers use Radio Telescopes to gather radiowaves from space which are used to generate visual images of galaxies not in the visible spectrum.. Visible galaxies can be captured with photography.
The best way to see visible galaxies and stars are through long exposure photography using available technologies like DSLR cameras by themselves or coupled to Telescopes.