Most of the letters are spelled in IPA as they would be in Spanish anyhow. eɪ, bi, si,di, i ...
The only problems you're likely to have are:
g, h, j, o, q, u, w, y.
w /dʌbl ju/
y /waɪ /
Anyhow, it would take you only an hour or two to master the consonants necessary for English, and perhaps another two hours for the vowels and diphthongs. It looks more complicated than it actually is. (Except for when you're trying to type them nicely on this blessèd software!)