You can use:

firstname1 = firstname1.replaceAll("[0-9]","");

This will remove all numeric values from String firstName1.

    String firstname1 = "S1234am";
    firstname1 = firstname1.replaceAll("[0-9]","");
    System.out.println(firstname1);//Prints Sam

You don't need to escape the ^, you can use \\d+ to match multiple digits, and \\. for a literal dot and you don't need multiple calls to replaceAll. For example,

private static String removeSignsFromName(String name) {
    return name.replaceAll("^\\d+\\.", "");
}

Which I tested like

public static void main(String[] args) {
    System.out.println(removeSignsFromName("23.Piano+trompet"));
}

And got

Piano+trompet

I would use a regex.

String text = "-jaskdh2367sd.27askjdfh23";
String digits = text.replaceAll("[^0-9.]", "");
System.out.println(digits);

prints

2367.2723

You might like to keep - as well for negative numbers.