Find & replace in a php file???

I feel really stupid for asking this, but how do you perform search and replace in a normal php file - no classes - just few functions?
Like this:
function com_install() {
    jimport('joomla.filesystem');
    $update = checkIfUpdating();

    switch($update) {
        case '1b':
            dropToolbars();
            updateFiles();
            updateSettings1b();
        case '1b2':
            updateFilesBeta2();    
        case '1stable':
            updateFiles1stable();
            updateSettings1stable();
        case '2.0':    
        case '2.0.1':    
        case '2.0.2':    
        case '2.0.3':    
        case '2.0.4':
            updateSettings204();
        case '2.0.5':
            updateDatabaseStructure205();
            break;
        case 'new':
            insertNewSettings();
            break;
    }
    
    if ($update != 'new') {
        updateVersionNumber();
    }

    installPlugins();
}

I have selected jimport and clicked on ctrl+R and i get cannot perform refactoring - selected function is not located inside this project. I don't want to refactor -> I just want to rename the function in that particular file?

I can select the directory and use the option "replace in path" -> it will find the text that I search for and I can replace from there, but this seems really overly complicated just for few changes in a file???

Am I missing something?