hey regex guru's

I have a data column that contains a substring similar to this:

'This is a string with ID=123 contained inside'

i need to replace the ID=123 with another fixed string say ID=1

i have a working REPLACE call that swaps out the values correctly, but this only works on a known original id number. I can extend to make it work when the number of digits are known by using some substr magic, however, the id number may have an arbitrary number of digits, so i'm thinking regex.

any help with the regex magix to grab the entire ID=999 substring no matter how many digits would be very helpful.

thanks